ARM: imx25: support silicon revision 1.2

Update the mx25_read_cpu_rev function to recognize silicon revision 1.2
for imx25 chipsets.

Silicon revision 1.2 is mentioned in the errata document at
https://www.nxp.com/docs/en/errata/IMX25CE.pdf. The imx25 chips on my
test boards show revision 1.2 as well.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/mach-imx/cpu-imx25.c

@@ -32,6 +32,8 @@ static int mx25_read_cpu_rev(void)
 		return IMX_CHIP_REVISION_1_0;
 	case 0x01:
 		return IMX_CHIP_REVISION_1_1;
+	case 0x02:
+		return IMX_CHIP_REVISION_1_2;
 	default:
 		return IMX_CHIP_REVISION_UNKNOWN;
 	}