[ARM] 4790/1: S3C2412: Fix parent selection for msysclk.

The msysclk clock was checking for the wrong PLL for the
parent in s3c2412_setparent_msysclk(), trying the UPLL instead
of the MPLL output.

Also ensure the mpll and fclks are at the same rate at init time.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>