feat(rme): save PAuth context when RME is enabled

This patch enables CTX_INCLUDE_PAUTH_REGS for RME builds.
The RMM-EL3 specification is also updated to reflect the changes
and also version of the same is bumped from 0.1 to 0.2.

Signed-off-by: Shruti Gupta <shruti.gupta@arm.com>
Change-Id: I2e96a592d2b75abaee24294240c1727c5ceba420