usb: musb: Add musb_clearb/w() interface

usb: musb: Add musb_clearb/w() interface

Delete the const attribute of addr parameter in readb/w/l hooks, these
changes are for implementing clearing W1C registers.
Replace musb_readb/w with musb_clearb/w to clear the interrupt status.

While at here, change some unsigned type to u32 to fix checkpatch.pl
warnings.

Signed-off-by: Min Guo <min.guo@mediatek.com>
[b-liu@ti.com: fix checkpatch.pl warnings.]
Signed-off-by: Bin Liu <b-liu@ti.com>
Link: https://lore.kernel.org/r/20200115132547.364-23-b-liu@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>