staging/xgifb: Consolidate XGI_EnableChISLCD and XGI_DisableChISLCD
staging/xgifb: Consolidate XGI_EnableChISLCD and XGI_DisableChISLCD

These two functions share the same code except one line - thus we can
simply merge them and add a parameter to switch between both variants.

Signed-off-by: Peter Huewe <014f16385c5a8ff1646b588a3d5169b595c0f10e@gmx.de>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs