Add BLX driver, disable by default

*Read more: http://forum.xda-developers.com/nexus-s/development/mod-battery-life-extender-blx-t1257497

	modified:   drivers/misc/Kconfig
	modified:   drivers/misc/Makefile
	new file:   drivers/misc/blx.c
	modified:   drivers/power/max17048_battery.c
	new file:   include/linux/blx.h