ArmVirtPkg: RMM 1.0-eac3 - Handle RsiSetIpaState() response

The RMM 1.0-eac3 specification extends the RSI_IPA_STATE_SET
command to return a new RsiResponse value to indicate if the
Host accepts or rejects the IPA state change request to RAM.

Therefore, define the RsiResponse enum and return an error
RETURN_ACCESS_DENIED if the Host rejects the RIPAS change
request to RAM.

Such a failure is fatal and not recoverable and the caller
is then expected to tear down the Realm.

Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>