The origianl understanding of clock is wrong. The UDC controller
only have one clock input.
Passing clock name by pdata is wrong. The clock is defined by device
iteself.

Cc: Chao Xie <chao.xie@marvell.com>
Cc: Yu Xu <yuxu@marvell.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>