plat/arm: Support for Cortex A5 in FVP Versatile Express platform

Cortex A5 doesnt support VFP, Large Page addressing and generic timer
which are addressed in this patch. The device tree for Cortex a5
is also included.

Change-Id: I0722345721b145dfcc80bebd36a1afbdc44bb678
Signed-off-by: Usama Arif <usama.arif@arm.com>