AArch32: Fix detection of virtualization support ...

The Virtualization field in the ID_PFR1 register has only 2
valid values (0 or 1) but it was incorrectly checked against
unrelated value tied to the SPSR register instead.

This patch fixes the detection of virtualization support by
using the valid values in BL1 context management code.

Change-Id: If12592e343770e1da90f0f5fecf0a3376047ac29

AArch32: Add generic changes in BL1 ...

This patch adds generic changes in BL1 to support AArch32 state.
New AArch32 specific assembly/C files are introduced and
some files are moved to AArch32/64 specific folders.
BL1 for AArch64 is refactored but functionally identical.
BL1 executes in Secure Monitor mode in AArch32 state.

NOTE: BL1 in AArch32 state ONLY handles BL1_RUN_IMAGE SMC.

Change-Id: I6e2296374c7efbf3cf2aa1a0ce8de0732d8c98a5