intel: Fix bufmgr_gem->gen for gen > 4

If the pci_device's actual gen was > 4, then we stupidly set
bufmgr_gem->gen = 6. Luckily this caused no bugs, and this fix shouldn't
change any behavior, because all checks against the gen currently have one
of the forms below:
    gen == 2
    gen == 3
    gen >= 4

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c
index 2b4fab1..26e3a5c 100644
--- a/intel/intel_bufmgr_gem.c
+++ b/intel/intel_bufmgr_gem.c
@@ -2321,8 +2321,14 @@
 		bufmgr_gem->gen = 3;
 	else if (IS_GEN4(bufmgr_gem->pci_device))
 		bufmgr_gem->gen = 4;
-	else
+	else if (IS_GEN5(bufmgr_gem->pci_device))
+		bufmgr_gem->gen = 5;
+	else if (IS_GEN6(bufmgr_gem->pci_device))
 		bufmgr_gem->gen = 6;
+	else if (IS_GEN7(bufmgr_gem->pci_device))
+        	bufmgr_gem->gen = 7;
+	else
+        	assert(0);
 
 	if (IS_GEN3(bufmgr_gem->pci_device) &&
 	    bufmgr_gem->gtt_size > 256*1024*1024) {