feat(rmm): rename system_rsi_abi_version()

This patch renames system_rsi_abi_version()
to handle_rsi_version() and doesn't make
any changes to functionality.

Signed-off-by: AlexeiFedorov <Alexei.Fedorov@arm.com>
Change-Id: If9b3291016cb85e1509b8c80f7fa06dba649a5d3
diff --git a/runtime/core/exit.c b/runtime/core/exit.c
index ab3ee2c..3f3618d 100644
--- a/runtime/core/exit.c
+++ b/runtime/core/exit.c
@@ -411,7 +411,7 @@
 		rec->regs[0] = SMCCC_VERSION_NUMBER;
 		break;
 	case SMC_RSI_ABI_VERSION:
-		rec->regs[0] = system_rsi_abi_version();
+		rec->regs[0] = handle_rsi_version();
 		break;
 	case SMC32_PSCI_FID_MIN ... SMC32_PSCI_FID_MAX:
 	case SMC64_PSCI_FID_MIN ... SMC64_PSCI_FID_MAX: {