plat: xilinx: Mask unnecessary bytes of return error code

Versal firmware adds extra error codes along with PM error codes
while sending response to driver. This makes incorrect error
identification at driver side.

To fix this, mask the unnecessary error bytes before sending the
error code to the driver.
Signed-off-by: Ravi Patel <ravi.patel@xilinx.com>
Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Change-Id: I18c2f3bd2d067e91344852c2f0c1bafea0e6eb23

plat/xilinx/common/pm_service/pm_ipi.c

@@ -18,6 +18,8 @@
 #include "pm_ipi.h"
 
 
+#define ERROR_CODE_MASK		0xFFFFU
+
 DEFINE_BAKERY_LOCK(pm_secure_lock);
 
 /**
@@ -230,7 +232,7 @@ enum pm_ret_status pm_ipi_send_sync(const struct pm_proc *proc,
 	if (ret != PM_RET_SUCCESS)
 		goto unlock;
 
-	ret = pm_ipi_buff_read(proc, value, count);
+	ret = ERROR_CODE_MASK & (pm_ipi_buff_read(proc, value, count));
 
 unlock:
 	bakery_lock_release(&pm_secure_lock);