drm/i915: Add ULL postfix to VGT_MAGIC constant

Without this Dave's 32bit rhel compiler is annoyed. Don't ask me about
the exact rules for this stuff though, but this should be safe.
Reported-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

drivers/gpu/drm/i915/i915_vgpu.h

@@ -32,7 +32,7 @@
  * The following structure pages are defined in GEN MMIO space
  * for virtualization. (One page for now)
  */
-#define VGT_MAGIC         0x4776544776544776	/* 'vGTvGTvG' */
+#define VGT_MAGIC         0x4776544776544776ULL	/* 'vGTvGTvG' */
 #define VGT_VERSION_MAJOR 1
 #define VGT_VERSION_MINOR 0