uboot-imx

mx31: Convert MX31_HCLK_FREQ and MX31_CLK32 to Kconfig.

Also remove the #ifdef's from clock.h since the Kconfig values defaults
the to old default values in clock.h.

Signed-off-by: Magnus Lilja <lilja.magnus@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>