ARM: tegra: clock: Account for memory BW efficiency

Account for memory efficiency when processing requests from Tegra3
EMC shared bandwidth users. Do not round requests from these users
until they are aggregated.

The respective debugfs node: /d/tegra_emc/efficiency (in %).

Bug 952739

Signed-off-by: Alex Frid <afrid@nvidia.com>
(cherry picked from commit 86929087f68c4366d6179101eb9a6a6473a4f084)

Change-Id: I4acdd89f44de1401ce5dad8fc4936932df014458
Reviewed-on: http://git-master/r/103499
Reviewed-by: Automatic_Commit_Validation_User
Tested-by: Aleksandr Frid <afrid@nvidia.com>
Reviewed-by: Jihoon Bang <jbang@nvidia.com>
Reviewed-by: Jon Mayo <jmayo@nvidia.com>
GVS: Gerrit_Virtual_Submit

Conflicts:
	arch/arm/mach-tegra/tegra3_clocks.c
	arch/arm/mach-tegra/tegra3_emc.c
	arch/arm/mach-tegra/tegra3_emc.h