Trying to do DFU on nRF5340 development kit with external flash MX66L1G

Question

Build environment is the nRF SDK Connect for VS Code extension with ncs 2.3.0. 
 I am trying to accomplish DFU over UART with mcumgr serial console in which primary slot will in internal flash of the development kit and secondary slot is in external flash MX66L1G. I am using static configuration for partition region using partition manager. The sample on which I am working is ncs\v2.3.0\zephyr\samples\subsys\mgmt\mcumgr\smp_svr 
 Here is my pm_static.yml file and prj.conf 
 EMPTY_0:
 address: 0xf000
 end_address: 0x11000
 placement:
 before:
 - mcuboot_pad
 region: flash_primary
 size: 0x2000
app:
 address: 0x11200
 end_address: 0x101000
 region: flash_primary
 size: 0xefe00
mcuboot:
 address: 0x0
 end_address: 0xf000
 placement:
 before:
 - mcuboot_primary
 region: flash_primary
 size: 0xf000
mcuboot_pad:
 address: 0x11000
 end_address: 0x11200
 placement:
 align:
 start: 0x8000
 before:
 - mcuboot_primary_app
 region: flash_primary
 size: 0x200
mcuboot_primary_app:
 address: 0x11200
 end_address: 0x101000
 orig_span: &id002
 - app
 region: flash_primary
 size: 0xefe00
 span: *id002
mcuboot_primary:
 address: 0x11000
 end_address: 0x101000
 orig_span: &id001
 - app
 - mcuboot_pad
 region: flash_primary
 size: 0xf0000
 span: *id001
mcuboot_secondary:
 address: 0x0
 device: DT_CHOSEN(nordic_pm_ext_flash)
 end_address: 0xf0000
 region: external_flash
 share_size:
 - mcuboot_primary
 size: 0xf0000
mcuboot_secondary_app:
 address: 0x0
 end_address: 0xefe00
 orig_span: &id003
 - app
 region: external_flash
 size: 0xefe00
 span: *id003
EMPTY_1:
 address: 0xf0000
 end_address: 0x8000000
 region: external_flash
 size: 0x7f10000
sram_primary:
 address: 0x20000000
 end_address: 0x20020000
 region: sram_primary
 size: 0x20000 # Enable the shell mcumgr transport.
CONFIG_SHELL=y
CONFIG_SHELL_BACKEND_SERIAL=y
CONFIG_MCUMGR_SMP_SHELL=y

# mcumgr-cli application doesn't accepts log in the channel it uses
CONFIG_SHELL_LOG_BACKEND=n

# Enable shell commands.
CONFIG_MCUMGR_CMD_SHELL_MGMT=y

#Enable MCUboot
CONFIG_BOOTLOADER_MCUBOOT=y

# Enable mcumgr.
CONFIG_MCUMGR=y

#Enable flash operations.
CONFIG_FLASH=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_FLASH_MAP=y
CONFIG_FPROTECT=y

# Enable most core commands.
CONFIG_MCUMGR_CMD_IMG_MGMT=y

# Enable logging
CONFIG_LOG=y
CONFIG_MCUBOOT_UTIL_LOG_LEVEL_DBG=y

# Disable debug logging
CONFIG_LOG_MAX_LEVEL=4

# DRivers enabled 
CONFIG_SPI=y

#Place MCUboot secondary in external flash
CONFIG_PM_EXTERNAL_FLASH_MCUBOOT_SECONDARY=y

CONFIG_NORDIC_QSPI_NOR=y

# Ensure an MCUboot-compatible binary is generated.
CONFIG_IMG_ERASE_PROGRESSIVELY=y

CONFIG_SERIAL=y
CONFIG_CONSOLE=y
CONFIG_UART_CONSOLE=y
 
 I have also created mcuboot.conf and mcuboot.overlay 
 /* Step 3.5 - Configure button and LED for Serial Recovery */

/{
 aliases {
 mcuboot-button0 = &button1;
 mcuboot-led0 = &led1;
 };
}; 
 These are the errors which I am facing while flashing the mcuboot 
 I am taking reference for DFU over UART from this link of Dev Academy Exercise 1 - DFU over UART - Nordic Developer Academy (nordicsemi.com) 
 
 Overlay file for the hardware nrf5340dk_nrf5340dk_cpuapp.overlay 
 
 Please help me figure out what is missing in this whole configuration and why am I getting these errors and warnings.