arm/arm64: smccc: Add SMCCC-specific return codes

We've so far used the PSCI return codes for SMCCC because they
were extremely similar. But with the new ARM DEN 0070A specification,
"NOT_REQUIRED" (-2) is clashing with PSCI's "PSCI_RET_INVALID_PARAMS".

Let's bite the bullet and add SMCCC specific return codes. Users
can be repainted as and when required.

Change-Id: Ia19dc183a646858569df488d8299d94f6429848a
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Git-commit: eff0e9e1078ea7dc1d794dc50e31baef984c46d7
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>