mx6: Read silicon revision from register

Instead of hardcoding the mx6 silicon revision, read it in run-time.

Also, besides the silicon version print the mx6 variant type: quad,dual/solo
or solo-lite.

Tested on a mx6qsabrelite, where it shows:

CPU:   Freescale i.MX6Q rev1.0 at 792 MHz

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Stefano Babic <sbabic@denx.de>
Acked-by: Jason Liu <r64343@freescale.com>
3 files changed