suit: flash_companion: Adjust minimal configuration

Adjust Kconfigs to match the new set of options and dependencies.

Ref: NCSDK-NONE

Signed-off-by: Tomasz Chyrowicz <tomasz.chyrowicz@nordicsemi.no>

Author: tomchy

samples/suit/flash_companion/prj.conf

@@ -26,14 +26,15 @@ CONFIG_IRQ_OFFLOAD=n
 
 # Disable memory protection
 CONFIG_THREAD_STACK_INFO=n
-CONFIG_THREAD_CUSTOM_DATA=n
+CONFIG_BUILTIN_STACK_GUARD=n
 
 # Disable unneeded ARM core functionality
 CONFIG_ARM_MPU=n
 CONFIG_FPU=n
 
 # Disable boot banner
 CONFIG_BOOT_BANNER=n
+CONFIG_NCS_BOOT_BANNER=n
 CONFIG_BOOT_DELAY=0
 
 # Disable serial communication