mach-sc5xx: Introduce Kconfig symbols for image addresses

mach-sc5xx: Introduce Kconfig symbols for image addresses

Add Kconfig symbols to parameterize the SPI flash layout used in a
default-ish configuration. This adds more flexibility to the default ADI
environment, enabling customers with boards based on but not identical
to an ezkit to reuse more of the infrastructure. Furthermore it allows
for yocto (the expected default) or binman (to be introduced in this
series) to configure or use the flash layout based on a single
definition of all of the parameters when creating an image.

Signed-off-by: Greg Malysa <malysagreg@gmail.com>
Signed-off-by: Utsav Agarwal <utsav.agarwal@analog.com>