feat(msm8916): add SP_MIN port for AArch32

Use the new shared msm8916 setup code to allow compiling the minimal
AArch32 Secure Payload (SP_MIN) as simple PSCI implementation.

AArch64 is preferred for the Cortex-A53 cores in MSM8916 but there are
some similar platforms with AArch32-only Cortex-A7 cores that can
benefit from this in future changes.

The AArch32 assembly implementation for msm8916_helpers.S and
uartdm_console.S is a direct port of the AArch64 implementation.
Only plat_get_my_entrypoint is slightly different because there is no
need to handle the "boot remapper" on cold boot for AArch32.

Change-Id: Idf160e86fb3e685fcedec3e051400e6273997b74
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
7 files changed