usb: phy: tegra remove include of <mach/iomap.h>

Almost nothing from this file is used, and the file will hopefully be
deleted soon. Copy the tiny portions that are used directly into
tegra_usb_phy.c. I believe that Venu Byravarasu is working on cleaning up
our USB driver, and those cleanups will remove the need for these
constants.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>