test(realm): add test for RSI_PLANE_REG_READ/WRITE command

test for RSI_PLANE_REG_READ/WRITE command

Signed-off-by: Shruti Gupta <shruti.gupta@arm.com>
Change-Id: I92e0aeef48c9b2abe26e5d3b2ea62669a22d4f8b
diff --git a/realm/realm_rsi.c b/realm/realm_rsi.c
index b2505cc..4e223ca 100644
--- a/realm/realm_rsi.c
+++ b/realm/realm_rsi.c
@@ -199,3 +199,28 @@
 			{RSI_PLANE_ENTER, plane_index, plane_run});
 	return res.ret0;
 }
+
+u_register_t rsi_plane_reg_read(u_register_t plane_index,
+				u_register_t register_encoding,
+				u_register_t *value)
+{
+	smc_ret_values res = {};
+
+	res = tftf_smc(&(smc_args)
+			{RSI_PLANE_REG_READ, plane_index, register_encoding});
+	if (res.ret0 == RSI_SUCCESS) {
+		*value = res.ret1;
+	}
+	return res.ret0;
+}
+
+u_register_t rsi_plane_reg_write(u_register_t plane_index,
+				 u_register_t register_encoding,
+				 u_register_t value)
+{
+	smc_ret_values res = {};
+
+	res = tftf_smc(&(smc_args)
+			{RSI_PLANE_REG_WRITE, plane_index, register_encoding, value});
+	return res.ret0;
+}