gxt4500: enable on non-PPC architectures

These chips can be present at least on x86 too - Fire GL2 AGP has GXT6000P but
this driver is currently limited to PPC.
Enable it for all architectures and add chip configuration for little-endian.

Tested on x86 with Fire GL2 AGP.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/fbdev/Kconfig

@@ -2134,7 +2134,7 @@ config FB_UDL
 
 config FB_IBM_GXT4500
 	tristate "Framebuffer support for IBM GXT4000P/4500P/6000P/6500P adaptors"
-	depends on FB && PPC
+	depends on FB
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -2142,7 +2142,8 @@ config FB_IBM_GXT4500
 	  Say Y here to enable support for the IBM GXT4000P/6000P and
 	  GXT4500P/6500P display adaptor based on Raster Engine RC1000,
 	  found on some IBM System P (pSeries) machines. This driver
-	  doesn't use Geometry Engine GT1000.
+	  doesn't use Geometry Engine GT1000. This driver also supports
+	  AGP Fire GL2/3/4 cards on x86.
 
 config FB_PS3
 	tristate "PS3 GPU framebuffer driver"

drivers/video/fbdev/gxt4500.c

@@ -670,8 +670,15 @@ static int gxt4500_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	pci_set_drvdata(pdev, info);
 
+#ifdef __BIG_ENDIAN
 	/* Set byte-swapping for DFA aperture for all pixel sizes */
 	pci_write_config_dword(pdev, CFG_ENDIAN0, 0x333300);
+#else /* __LITTLE_ENDIAN */
+	/* not sure what this means but fgl23 driver does that */
+	pci_write_config_dword(pdev, CFG_ENDIAN0, 0x2300);
+/*	pci_write_config_dword(pdev, CFG_ENDIAN0 + 4, 0x400000);*/
+	pci_write_config_dword(pdev, CFG_ENDIAN0 + 8, 0x98530000);
+#endif
 
 	info->fbops = &gxt4500_ops;
 	info->flags = FBINFO_FLAG_DEFAULT;