cpu: imx8: show RevC instead of Rev? at boot log

Add REVC informaiton.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>

arch/arm/include/asm/arch-imx/cpu.h

@@ -64,6 +64,7 @@
 
 #define CHIP_REV_A		0x0
 #define CHIP_REV_B		0x1
+#define CHIP_REV_C		0x2
 
 #define BOARD_REV_1_0           0x0
 #define BOARD_REV_2_0           0x1

drivers/cpu/imx8_cpu.c

@@ -43,6 +43,8 @@ const char *get_imx8_rev(u32 rev)
 		return "A";
 	case CHIP_REV_B:
 		return "B";
+	case CHIP_REV_C:
+		return "C";
 	default:
 		return "?";
 	}