feat(spmc): add FFA_PARTITION_INFO_GET_REGS

Add basic and incomplete implementation of FFA_PARTITION_INFO_GET_REGS
ABI. This new ABI allows to get partition information without the need
for rx/tx buffer and helps in situations where having an rx/tx buffer
mapped and available is difficult (ex. uefi runtime services).
The implementation simply returns error now and future patches will add
functionality.

Signed-off-by: Raghu Krishnamurthy <raghu.ncstate@gmail.com>
Change-Id: I5084581cee02927569366877333b120f75137781
diff --git a/src/api.c b/src/api.c
index 452ba78..71e156e 100644
--- a/src/api.c
+++ b/src/api.c
@@ -418,6 +418,18 @@
 				  .arg3 = partition_info_size};
 }
 
+struct ffa_value api_ffa_partition_info_get_regs(struct vcpu *current,
+						 const struct ffa_uuid *uuid,
+						 const uint16_t start_index,
+						 const uint16_t tag)
+{
+	(void)current;
+	(void)uuid;
+	(void)start_index;
+	(void)tag;
+	return ffa_error(FFA_NOT_SUPPORTED);
+}
+
 struct ffa_value api_ffa_partition_info_get(struct vcpu *current,
 					    const struct ffa_uuid *uuid,
 					    const uint32_t flags)
@@ -2260,6 +2272,7 @@
 	case FFA_MEM_PERM_GET_64:
 	case FFA_MEM_PERM_SET_64:
 	case FFA_MSG_SEND2_32:
+	case FFA_PARTITION_INFO_GET_REGS_64:
 #endif
 		return (struct ffa_value){.func = FFA_SUCCESS_32};