x86/gart: Do not select AGP for GART_IOMMU

There is no dependency from the gart code to the agp code.
And since a lot of systems today do not have agp anymore
remove this dependency from the kernel configuration.
Signed-off-by: Pavel Vasilyev <pavel@pavlinux.ru>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

arch/x86/Kconfig

@@ -586,7 +586,6 @@ config GART_IOMMU
 	bool "GART IOMMU support" if EMBEDDED
 	default y
 	select SWIOTLB
-	select AGP
 	depends on X86_64 && PCI
 	---help---
 	  Support for full DMA access of devices with 32bit memory access only