aarch64: add basic Aarch32 support

aarch64: add basic Aarch32 support

Add database for common, equivalent opcodes for Aarch32 and
Aarch64 execution states

Revisit all functions that access Aarch64 specific registers
or use Aarch64 opcodes and rewrite them to act depending on
current state of the core.

Add core register access functions for Aarch32 state

Add function to determine the core execution state without
reading DSPSR.

Change-Id: I345e9f6d682fb4ba454e4b1d16bb5e1b27570691
Signed-off-by: Matthias Welwarsky <matthias.welwarsky@sysgo.com>