zynqmp: Ignore the revision field of the IDCODE

The revision field may change between silicon revisions without changing
the mapping to a part. This avoids errors like:
  ERROR: Incorrect XILINX IDCODE 0x14738093, maskid 0x4600093
  NOTICE: ATF running on XCZUUNKN/EP108 v3/RTL5.1 at 0xfffe5000
on parts with a newer revision.
Reported-by: Love Kumar <love.kumar@xilinx.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: Alistair Francis <alistair.francis@xilinx.com>
Tested-by: Love Kumar <love.kumar@xilinx.com>

plat/xilinx/zynqmp/aarch64/zynqmp_common.c

@@ -183,11 +183,9 @@ static char *zynqmp_print_silicon_idcode(void)
 
 	tmp = id;
 	tmp &= ZYNQMP_CSU_IDCODE_XILINX_ID_MASK |
-	       ZYNQMP_CSU_IDCODE_FAMILY_MASK |
-	       ZYNQMP_CSU_IDCODE_REVISION_MASK;
+	       ZYNQMP_CSU_IDCODE_FAMILY_MASK;
 	maskid = ZYNQMP_CSU_IDCODE_XILINX_ID << ZYNQMP_CSU_IDCODE_XILINX_ID_SHIFT |
-		 ZYNQMP_CSU_IDCODE_FAMILY << ZYNQMP_CSU_IDCODE_FAMILY_SHIFT |
-		 ZYNQMP_CSU_IDCODE_REVISION << ZYNQMP_CSU_IDCODE_REVISION_SHIFT;
+		 ZYNQMP_CSU_IDCODE_FAMILY << ZYNQMP_CSU_IDCODE_FAMILY_SHIFT;
 	if (tmp != maskid) {
 		ERROR("Incorrect XILINX IDCODE 0x%x, maskid 0x%x\n", id, maskid);
 		return "UNKN";