feat(realm): add support for RSI_IPA_STATE_GET/SET

Add support for realm API rsi_ipa_state_set, rsi_ipa_state_get
Add testcase for following
* Realm calls rsi_ipa_state_set to change RIPAS=RAM,
* Host accepts and call RMI_RTT_SET_RIPAS
* Realm verifies RIPAS change was successful

Change-Id: I4da6c7d25faa62afde1d0f682510bac6c8445821
Signed-off-by: Shruti Gupta <shruti.gupta@arm.com>
8 files changed