init: Initialize VGA IOBase before using it

The NV driver did never set the VGA IOBase for those registers which
have different addresses dependent whether the VGA engine is running in
mono or color mode.
This has not been detected as the VGA mode and font save/restore
functions initialize this value themselves.

Signed-off-by: Egbert Eich <eich@freedesktop.org>
Reviewed-by: Mark Kettenis <kettenis@openbsd.org>

src/nv_setup.c

@@ -491,6 +491,8 @@ NVCommonSetup(ScrnInfoPtr pScrn)
 
     pNv->Television = FALSE;
 
+    vgaHWGetIOBase(pVga);
+
     if(!pNv->twoHeads) {
        pNv->CRTCnumber = 0;
        if((monitorA = NVProbeDDC(pScrn, 0))) {