mx25: add CPU revision 1.2

tested on a MCIMX257CJM4A which now reports :
CPU:   Freescale i.MX25 rev1.2 at 399 MHz

Signed-off-by: Eric BĂ©nard <eric@eukrea.com>
Acked-by: Otavio Salvador <otavio@ossystems.com.br>
2 files changed