galaxys2: fix corrupt power off charging graphics

Seems that our charger graphics.c does not like 32bit PNGs
Converted images to 24bit PNGs and everything works fine

Change-Id: I68971a7d0c4ca89205950cbfedafed5ece479308
Merge branch 'kk4.4' of https://github.com/SlimRoms/device_samsung_galaxys2-common into kk4.4