ARM: OMAP: SmartReflex driver integration

ARM: OMAP: SmartReflex driver integration

This patch integrates TI's SmartReflex driver into linux-omap. SmartReflex is
a module that adjusts OMAP3 VDD1 and VDD2 operating voltages around the
nominal values of current operating point depending on silicon
characteristics and operating conditions.

The patch adds Kconfig options "SmartReflex support" and a sub-option
"SmartReflex testing support" under "System type"->"TI OMAP implementations"
menu. The testing support can be used to test SmartReflex functionality, if
the E-fuse values have not been set for the device. It however uses software
hard coded sensor parameters, which may not work on all devices. Beware.

The driver creates two sysfs entries into /sys/power/ named
"sr_vdd1_autocomp" and "sr_vdd2_autocomp" which can be used to activate
voltage autocompensation feature of SmartReflex modules 1 and 2.

Use the following commands to enable autocompensation:

echo -n 1 > /sys/power/sr_vdd1_autocomp
echo -n 1 > /sys/power/sr_vdd2_autocomp

To disable:

echo -n 0 > /sys/power/sr_vdd1_autocomp
echo -n 0 > /sys/power/sr_vdd2_autocomp

Signed-off-by: Kalle Jokiniemi <ext-kalle.jokiniemi@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>