feat(lib/arch): add support for FEAT_DoubleFault2 to RMM

This patch adds support to RMM to handle the case when
FEAT_DoubleFault2 is present and the Realm has set the
sctlr2_el1.ease bit.

The patch also enables FEAT_DoubleFault2 on the Shrinkwrap model for
rmm-tftf tests.

Closes #33

Signed-off-by: Javier Almansa Sobrino <javier.almansasobrino@arm.com>
Change-Id: I27d9c9b21d1939c85f3a3d7089bceb9348aaa4c5
8 files changed