ARM: tegra: remove tegra EMC scaling driver

Nothing calls into the Tegra EMC (External Memory Controller) scaling
driver any more, so it's dead code. Remove it.

Cc: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

diff --cc arch/arm/mach-tegra/Makefile
Simple merge

diff --cc arch/arm/mach-tegra/tegra2_emc.c
Simple merge

diff --cc arch/arm/mach-tegra/tegra2_emc.h
Simple merge