Use uintptr_t as base address type in ARM driver APIs

Use uintptr_t as base address type in ARM driver APIs

This patch changes the type of the base address parameter in the
ARM device driver APIs to uintptr_t (GIC, CCI, TZC400, PL011). The
uintptr_t type allows coverage of the whole memory space and to
perform arithmetic operations on the addresses. ARM platform code
has also been updated to use uintptr_t as GIC base address in the
configuration.

Fixes ARM-software/tf-issues#214

Change-Id: I1b87daedadcc8b63e8f113477979675e07d788f1