ARM: OMAP2+: Configure voltage controller for cpcap

We can configure voltage controller for cpcap with the data available in
Motorola Mapphone Android Linux kernel. Let's add it so we can have droid4
behave the same way for voltage controller as other omap4 devices and save
some power when idle.

Note that we're now using high-speed i2c mode, looks like the Motorola
kernel had a typo using 0x200 instead of 200 for the timings which may
caused it to not work properly.

Also note that in the long run, this should just become dts data for a
voltage controller device driver. But let's get things working first to
make it possible to test further changes easily.

Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Sebastian Reichel <sre@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Tony Lindgren <tony@atomide.com>