soong: Add Cortex-A32 definitions

Add definitions for the Cortex-A32 CPU. This is an aarch32 only ARMv8-A
core. See more here https://developer.arm.com/Processors/Cortex-A32

 .

Test: added new minidroid target using this CPU variant and built
Change-Id: Id2351a43b9c6cb9785ef469b8c13fadd8b6324b8
Signed-off-by: Mark Slevinsky <markslevinsky@google.com>
Signed-off-by: Jesus Sanchez-Palencia <jesussanp@google.com>