encore: configure Vmmc2 as fixed voltage regulator instead of via PMIC

It appears that encore's PMIC doesn't have a Vmmc2 regulator, but we've
been attempting to set one up in the TWL anyway -- presumably for the
side effect of telling the MMC subsystem the input voltage it has
available.  The "correct" way of doing this is to set up a "fixed
regulator" which tells the kernel the voltage of the Vmmc2 supply.
ARM: OMAP3: TWL4030: ensure sys_nirq1 is mux'd and wakeup enabled

The SYS_NIRQ1 pin is the interupt line for the PMIC part of the TWL6030
and interrupts from the PMIC are needed as wakeup sources.

Ensure this pin is mux'd as input and has wakeup enabled so PMIC
interupts (e.g. RTC) can be used as wakeup sources.

Tested on 3430/n900, OMAP3530/Overo Fire, 3730/Overo FireSTORM,
3730/Beagle-xM.

Signed-off-by: Kevin Hilman <khilman@ti.com>
[steven@steven676.net: make apply to 3.0]
encore defconfigs: enable more filesystem I/O charsets

Requested by XDA user kyakace.