imx: mx6 correct get_cpu_rev

The DIGPROG register map:
23 ------- 16 | 15 ------ 8 | 7 --- 0 |
 Major upper  | Major Lower |  Minor  |

We also need to account for Major Lower.

Signed-off-by: Ye.Li <B37916@freescale.com>
Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
1 file changed