Fix MISRA Rule 5.3 Part 2

Use a _ prefix for Macro arguments to prevent that argument from
hiding variables of the same name in the outer scope

Rule 5.3: An identifier declared in an inner scope shall not
          hide an identifier declared in an outer scope

Fixed For:
    make LOG_LEVEL=50 PLAT=fvp

Change-Id: I67b6b05cbad4aeca65ce52981b4679b340604708
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>
diff --git a/drivers/arm/gic/v3/gicv3_private.h b/drivers/arm/gic/v3/gicv3_private.h
index db485d2..e1c0775 100644
--- a/drivers/arm/gic/v3/gicv3_private.h
+++ b/drivers/arm/gic/v3/gicv3_private.h
@@ -27,20 +27,20 @@
  * GICD_IROUTER. Bits[31:24] in the MPIDR are cleared as they are not relevant
  * to GICv3.
  */
-#define gicd_irouter_val_from_mpidr(mpidr, irm)		\
-	((mpidr & ~(0xff << 24)) |			\
-	 (irm & IROUTER_IRM_MASK) << IROUTER_IRM_SHIFT)
+#define gicd_irouter_val_from_mpidr(_mpidr, _irm)		\
+	((_mpidr & ~(0xff << 24)) |			\
+	 (_irm & IROUTER_IRM_MASK) << IROUTER_IRM_SHIFT)
 
 /*
  * Macro to convert a GICR_TYPER affinity value into a MPIDR value. Bits[31:24]
  * are zeroes.
  */
 #ifdef AARCH32
-#define mpidr_from_gicr_typer(typer_val)	(((typer_val) >> 32) & 0xffffff)
+#define mpidr_from_gicr_typer(_typer_val)	(((_typer_val) >> 32) & 0xffffff)
 #else
-#define mpidr_from_gicr_typer(typer_val)				 \
-	(((((typer_val) >> 56) & MPIDR_AFFLVL_MASK) << MPIDR_AFF3_SHIFT) | \
-	 (((typer_val) >> 32) & 0xffffff))
+#define mpidr_from_gicr_typer(_typer_val)				 \
+	(((((_typer_val) >> 56) & MPIDR_AFFLVL_MASK) << MPIDR_AFF3_SHIFT) | \
+	 (((_typer_val) >> 32) & 0xffffff))
 #endif
 
 /*******************************************************************************