x86, k8: Rename k8.[ch] to amd_nb.[ch] and CONFIG_K8_NB to CONFIG_AMD_NB

The file names are somehow misleading as the code is not specific to
AMD K8 CPUs anymore. The files accomodate code for other AMD CPU
northbridges as well.

Same is true for the config option which is valid for AMD CPU
northbridges in general and not specific to K8.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20100917160343.GD4958@loge.amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index cea0cd9..7fd41f0 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -670,7 +670,7 @@
 	bool "GART IOMMU support" if EMBEDDED
 	default y
 	select SWIOTLB
-	depends on X86_64 && PCI && K8_NB
+	depends on X86_64 && PCI && AMD_NB
 	---help---
 	  Support for full DMA access of devices with 32bit memory access only
 	  on systems with more than 3GB. This is usually needed for USB,
@@ -2076,7 +2076,7 @@
 
 endif # X86_32
 
-config K8_NB
+config AMD_NB
 	def_bool y
 	depends on CPU_SUP_AMD && PCI