Define registers for FEAT_RNG support

Add ISAR0 feature register read helper, location
of FEAT_RNG bits, feature support helper and the
rndr/rndrrs register read helpers.

Signed-off-by: Tomas Pilar <tomas@nuviainc.com>
Change-Id: I2a785a36f62a917548e55892ce92fa8b72fcb99d
3 files changed