agp/intel: Add gma_bus_addr

It is no longer used in the i915 code, so isolate it from the shared
struct.

This was originally part of:
commit 0e275518f325418d559c05327775bff894b237f7
Author: Ben Widawsky <ben@bwidawsk.net>
Date:   Mon Jan 14 13:35:33 2013 -0800

    agp/intel: decouple more of the agp-i915 sharing
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>

That commit had some other hunks which can't be used due to issues
Daniel found in previous commits.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
[danvet: drop squash notice from the commit since it's imo ok to keep
this one separate.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/char/agp/intel-gtt.c

@@ -79,6 +79,7 @@ static struct _intel_private {
 	int refcount;
 	/* Whether i915 needs to use the dmar apis or not. */
 	unsigned int needs_dmar : 1;
+	phys_addr_t gma_bus_addr;
 } intel_private;
 
 #define INTEL_GTT_GEN	intel_private.driver->gen
@@ -625,7 +626,7 @@ static int intel_gtt_init(void)
 		pci_read_config_dword(intel_private.pcidev, I915_GMADDR,
 				      &gma_addr);
 
-	intel_private.base.gma_bus_addr = (gma_addr & PCI_BASE_ADDRESS_MEM_MASK);
+	intel_private.gma_bus_addr = (gma_addr & PCI_BASE_ADDRESS_MEM_MASK);
 
 	return 0;
 }
@@ -781,7 +782,7 @@ static int intel_fake_agp_configure(void)
 	    return -EIO;
 
 	intel_private.clear_fake_agp = true;
-	agp_bridge->gart_bus_addr = intel_private.base.gma_bus_addr;
+	agp_bridge->gart_bus_addr = intel_private.gma_bus_addr;
 
 	return 0;
 }

include/drm/intel-gtt.h

@@ -11,8 +11,6 @@ struct intel_gtt {
 	/* Part of the gtt that is mappable by the cpu, for those chips where
 	 * this is not the full gtt. */
 	unsigned int gtt_mappable_entries;
-	/* needed for ioremap in drm/i915 */
-	phys_addr_t gma_bus_addr;
 } *intel_gtt_get(void);
 
 int intel_gmch_probe(struct pci_dev *bridge_pdev, struct pci_dev *gpu_pdev,