ARM: tegra: fix compilation error due to mach/hardware.h removal

This fixes a compilation error in cpu-tegra.c which was introduced in
dc8d966b

 ("ARM: convert PCI defines to variables") which removed the
now obsolete mach/hardware.h from the mach-tegra subtree.

Signed-off-by: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>