staging: xgifb: move XGINew_SenseLCD() to vb_init.c

The function is used only in vb_init.c, so move it there and make
it static.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>