Merge pull request #1784 from antonio-nino-diaz-arm/an/includes-arm

plat/arm: Cleanup of includes and drivers

plat/arm: mhu: Move to drivers/ folder

Change-Id: I656753a1825ea7340a3708b950fa6b57455e9056
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>