usb: dwc3: changes for v3.4 merge window

Here are the changes for v3.4 merge window.

It includes a new glue layer for Samsung's Exynos platform, a simplification of
memory management on DWC3 driver by using dev_xxx functions, a few
optimizations to IRQ handling by dropping memcpy() and using bitshifts, a fix
for TI's OMAP5430 TX Fifo Allocation, two fixes on USB2 test mode
implementation (one on debugfs and one on ep0), and several minor changes such
as whitespace cleanups, simplification of a few parts of the code, decreasing a
long delay to something a bit saner, dropping a header which was included twice
and so on.

The highlight on this merge is the support for Samsung's Exynos platform,
increasing the number of different users for this driver to three.

Note that Samsung Exynos glue layer will only compile on platforms which
provide implementation for the clk API for now. Once Samsung supports
pm_runtime, that limitation can be dropped from the Makefile.

Conflicts:
	drivers/usb/dwc3/gadget.c