defconfig: don't use SAMSUNG_CHARGER_SPEC
mmio: register rear flash as LED

courtesy @Meticulus
BLN: add rear cam flash.

-Not sure how useful this will be but I wanted to see if I could do
it. Works well. See notes in code for details.

-Use /sys/devices/virtual/misc/backlightnotification/blink_modes
to changes modes.

-Also fixed issue when blink_mode = 0 and backlight buttons stay
on.

Conflicts:

	drivers/misc/bln.c
	drivers/staging/mmio/st_mmio.c
Revert "defconfig: don't use SAMSUNG_CHARGER_SPEC"
bln: underping bln_blink_mode