iMX8MQ: Recognize the B2 revision

i.MX8MQ B2 is using same value in OCOTP_READ_FUSE_DATA like B1, so
we have to check the ROM verision to distinguish the revision.

As we have checked the B1 rev for sticky bits work around in
secure boot. So it won't apply on B2.

Signed-off-by: Ye Li <ye.li@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/include/asm/arch-imx/cpu.h b/arch/arm/include/asm/arch-imx/cpu.h
index 28244d7..ef090eb 100644
--- a/arch/arm/include/asm/arch-imx/cpu.h
+++ b/arch/arm/include/asm/arch-imx/cpu.h
@@ -65,6 +65,7 @@
 #define CHIP_REV_1_5            0x15
 #define CHIP_REV_2_0            0x20
 #define CHIP_REV_2_1            0x21
+#define CHIP_REV_2_2            0x22
 #define CHIP_REV_2_5            0x25
 #define CHIP_REV_3_0            0x30
 
diff --git a/arch/arm/mach-imx/imx8m/soc.c b/arch/arm/mach-imx/imx8m/soc.c
index f322488..f3b9f2d 100644
--- a/arch/arm/mach-imx/imx8m/soc.c
+++ b/arch/arm/mach-imx/imx8m/soc.c
@@ -410,7 +410,16 @@
 			 * 0xff0055aa is magic number for B1.
 			 */
 			if (readl((void __iomem *)(OCOTP_BASE_ADDR + 0x40)) == 0xff0055aa) {
-				reg = CHIP_REV_2_1;
+				/*
+				 * B2 uses same DIGPROG and OCOTP_READ_FUSE_DATA value with B1,
+				 * so have to check ROM to distinguish them
+				 */
+				rom_version = readl((void __iomem *)ROM_VERSION_B0);
+				rom_version &= 0xff;
+				if (rom_version == CHIP_REV_2_2)
+					reg = CHIP_REV_2_2;
+				else
+					reg = CHIP_REV_2_1;
 			} else {
 				rom_version =
 					readl((void __iomem *)ROM_VERSION_A0);