linux-wandboard

ENGR00176974 MX6Q: make 624M WP work, change 624 WP to 672 WP

since pll1 have a limit that cannot scaling down to 650M and below
so change the 600M WP to 672MHz.

otherwise, the 600WP's clock will depens on last frequency.

Signed-off-by: Zhang Jiejing <jiejing.zhang@freescale.com>