usb: chipidea: drop unused msm register definitions

These definitions are unused, and the same registers are also defined
in <linux/usb/msm_hsusb_hw.h>.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>