fix(xilinx): resolve misra rule 10.4 violations

Fixed below MISRA violation:
- MISRA Violation: MISRA-C:2012 R.10.4:
  - Both operands of an operator in which the usual arithmetic conversions
    are performed shall have the same essential type category.
- Fix:
  - Made data type same for both the operands.

Change-Id: I0cea19477f3c10265d95ea1d5d2ea151dbf174bb
Signed-off-by: Devanshi Chauhan Alpeshbhai <devanshi.chauhanalpeshbhai@amd.com>
diff --git a/plat/xilinx/common/ipi.c b/plat/xilinx/common/ipi.c
index 3e6a64e..18ae096 100644
--- a/plat/xilinx/common/ipi.c
+++ b/plat/xilinx/common/ipi.c
@@ -140,13 +140,12 @@
  * @local: local IPI ID.
  * @remote: remote IPI ID.
  *
- * Return: 0 idle, positive value for pending sending or receiving,
- *         negative value for errors.
+ * Return: 0 idle and positive value for pending sending or receiving.
  *
  */
-int ipi_mb_enquire_status(uint32_t local, uint32_t remote)
+uint32_t ipi_mb_enquire_status(uint32_t local, uint32_t remote)
 {
-	int ret = (int)PM_RET_SUCCESS;
+	uint32_t ret = (uint32_t)PM_RET_SUCCESS;
 	uint32_t status;
 	uint64_t obr_offset = (uint64_t)(IPI_REG_BASE(local) + IPI_OBR_OFFSET);
 	uint64_t isr_offset = (uint64_t)(IPI_REG_BASE(local) + IPI_ISR_OFFSET);