mx35: Fix clock dividers

The clock dividers that were used do not match at all the reference manual. They
were either completely broken, or came from an early silicon revision
incompatible with the current one.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Cc: Stefano Babic <sbabic@denx.de>