ARM: ux500: get rid of <mach/[hardware|db8500-regs].h>

This removes <mach/hardware.h> and <mach/db8500-regs.h>
from the Ux500, merging them into the local include
"db8500-regs.h" in mach-ux500. There is some impact
outside the ux500 machine, but most of it is dealt with
in earlier patches.

Contains portions of a clean-up patch from Arnd Bergmann.

Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>