[AGPGART] VIA and SiS AGP chipsets are x86-only

There's no point in troubling the Alpha, IA-64, PowerPC and PARISC
people with SiS and VIA options.  Andrew thinks it helps find bugs,
but there's no evidence of that.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Dave Jones <davej@redhat.com>

drivers/char/agp/Kconfig

@@ -86,7 +86,7 @@ config AGP_NVIDIA
 
 config AGP_SIS
 	tristate "SiS chipset support"
-	depends on AGP
+	depends on AGP && X86
 	help
 	  This option gives you AGP support for the GLX component of
 	  X on Silicon Integrated Systems [SiS] chipsets.
@@ -103,7 +103,7 @@ config AGP_SWORKS
 
 config AGP_VIA
 	tristate "VIA chipset support"
-	depends on AGP
+	depends on AGP && X86
 	help
 	  This option gives you AGP support for the GLX component of
 	  X on VIA MVP3/Apollo Pro chipsets.