uboot-imx

ARM: at91: clock: add UTMI PLL enable/disable function

To avoid the duplicated code, add the UTMI PLL handle functions,
and add PMC_USB init function too.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Tested-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Andreas Bießmann <andreas.devel@googlemail.com>