viafb: use proper pci config API

This patch alters viafb to use the proper Linux in-kernel API to access
PCI configuration space, rather than poking at I/O ports by itself.

Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: ScottFang@viatech.com.cn
Cc: JosephChan@via.com.tw
Signed-off-by: Harald Welte <HaraldWelte@viatech.com>
diff --git a/drivers/video/via/viafbdev.c b/drivers/video/via/viafbdev.c
index b7018ef..8af405b 100644
--- a/drivers/video/via/viafbdev.c
+++ b/drivers/video/via/viafbdev.c
@@ -1782,6 +1782,10 @@
 	viafb_init_chip_info(pdev, ent);
 	viaparinfo->fbmem = pci_resource_start(pdev, 0);
 	viaparinfo->memsize = viafb_get_fb_size_from_pci();
+	if (viaparinfo->memsize < 0) {
+		rc = viaparinfo->memsize;
+		goto out_delete_i2c;
+	}
 	viaparinfo->fbmem_free = viaparinfo->memsize;
 	viaparinfo->fbmem_used = 0;
 	viafbinfo->screen_base = ioremap_nocache(viaparinfo->fbmem,