OMAP4460: TWL/TPS data: update retention voltages to spec rev 0.3

Update retention voltages from Operating Conditions Data Manual
Addendum Revision 0.3 (August 2011).

OFF voltage is also updated as per requirement of 4460 OFF mode
conditions.

Change-Id: I558f0a483911b2616d0a19f9272a03258e35904a
Signed-off-by: Nishanth Menon <nm@ti.com>

Conflicts:
	arch/arm/mach-omap2/omap_twl.c
OMAPDSS: DISPC: Pipe threshold sizes power optimization.

This patch changes the calculation of thresholds and sets low
threshold to half of buffer size for OMAP4. The memory will
able to sleep between transactions to dss because dss will
read by big chunks.

boype: Also removed dispc_calculate_threshold function, as it is no longer used.

Backport from TI omapzoom kernel 3.4 repo, based upon:
http://git.omapzoom.org/?p=kernel/omap.git;a=commit;h=cd99eb345e1ad26ffbc665f46ea917dad762937b
voltage.h: OMAP4_VP_IVA_VLIMITTO_VDDMIN & OMAP4_VP_CORE_VLIMITTO_VDDMIN back to stock; increase OMAP4_VP_MPU_VLIMITTO_VDDMIN by 200000
This should counter the instabilities some users reported on r15.
mm/page_alloc.c: min_free_kbytes to 8192
The UI got laggy after approx. one day on-time with moderate use - let's see if this is making things better.
Linux 3.0.74
Fancy Kernel r16