arch: arm: aarch32: introduce CONFIG_BUILD_ALIGN_LMA

Introduce CONFIG_BUILD_ALIGN_LMA. When enabled, this symbol will add a
padding section after the final read only data section in the image.
This padding section will ensure that the LMA of the data sections
follows the same alignment restrictions as the VMA does. This LMA alignment
is needed for objcopy to adjust the LMA address of the output ELF file.

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>