fix(xilinx): resolve misra rule 4.5 violations

Fixed below MISRA violation:
- MISRA Violation: MISRA-C:2012 R.4.5:
  - Identifiers in the same name space with overlapping visibility should
    be typographically unambiguous.
- Fix:
  - Renamed PM_RET_ERROR_NOFEATURE to PM_RET_ERROR_IOCTL_NOT_SUPPORTED
    and removed unnecessary macro definitions.

Change-Id: I6f03e619979685df7418fbccad7b0934d136776e
Signed-off-by: Devanshi Chauhan Alpeshbhai <devanshi.chauhanalpeshbhai@amd.com>
diff --git a/plat/amd/versal2/plat_psci.c b/plat/amd/versal2/plat_psci.c
index d53d751..cded1f3 100644
--- a/plat/amd/versal2/plat_psci.c
+++ b/plat/amd/versal2/plat_psci.c
@@ -19,7 +19,6 @@
 #include <plat_private.h>
 #include <pm_defs.h>
 
-#define PM_RET_ERROR_NOFEATURE U(19)
 #define ALWAYSTRUE true
 #define LINEAR_MODE BIT(1)
 
@@ -192,7 +191,7 @@
 	case IOCTL_USB_SET_STATE:
 		break;
 	default:
-		ret = PM_RET_ERROR_NOFEATURE;
+		ret = PM_RET_ERROR_IOCTL_NOT_SUPPORTED;
 		break;
 	}