KVM: arm64: Allow pKVM on v1.0 compatible FF-A implementations

pKVM initialization fails on systems with v1.1+ FF-A implementations, as
the hyp does a strict match on the returned version from FFA_VERSION.
This is a stronger assertion than required by the specification, which
requires minor revisions be backwards compatible with earlier revisions
of the same major version.

Relax the check in hyp_ffa_init() to only test the returned major
version. Even though v1.1 broke ABI, the expectation is that firmware
incapable of using the v1.0 ABI return NOT_SUPPORTED instead of a valid
version.

Acked-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230718184537.3220867-1-oliver.upton@linux.dev


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>