usb: dwc3: omap: Adding am437x specific register map changes

usb: dwc3: omap: Adding am437x specific register map changes

AM437x and OMAP5 dwc3 subsytem have different register map.
Major differences are as follows.

OMAP5 has one main interrupt and one misc interrupt
Aegis has four main interrupts and one misc interrupt.

Miscellanous Interrupt offsets are changed.
UTMI OTG Control and Status Registers offsets are changed.
DEBUG Configuration and Status Registers are changed.

The main intend of the patch is to re-use the same wrapper driver
for both OMAP5 and AM437x, by using the x_major in revision
register and adjusting the offsets.

This patch adds the register map offsets and adds offset variables
in struct dwc3_omap to cache the offsets

Signed-off-by: George Cherian <george.cherian@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>