arch: arm: select ARM_GIC even for targets with gic-v3

Some of the features like MSM_GIC_SHOW_IRQ are using ARM_GIC
flag. So select this even for gic-v3 target on 32-bit.
This will also make it consistent with arm64 where ARM_GIC
is selected along with gic-v3.

Change-Id: Ie929d63a23c88799c488c5a79c81cd1cbfaa6565
Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>