staging/xgifb: Inline XGINew_SetDRAMSizingType

Since the function XGINew_SetDRAMSizingType is only called from one
location and consist only of 2 valuable lines we can simply inline it
here.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>