test(tftf): test PAuth in Realm

- Enable PAuth in Realm RL1 by default.
- Check if PAuth keys are accessible in Realm RL1.
- Check if Realm PAuth keys are preserved across RMM entry/exit.
- Check if NS PAuth keys are preserved across RMM entry/exit.
- Generate PAuth fault by cloberring LR.

Signed-off-by: Shruti Gupta <shruti.gupta@arm.com>
Change-Id: I85d8e03ec604c96117555e7aa866453cb2745cfe
12 files changed