drm/i915_drm.h: fix a typo

 'rbiter' -> 'arbiter'

Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230529112956.2083389-1-suijingfeng@loongson.cn

Author: Sui Jingfeng

include/drm/i915_drm.h

@@ -42,7 +42,7 @@ extern struct resource intel_graphics_stolen_res;
  * The Bridge device's PCI config space has information about the
  * fb aperture size and the amount of pre-reserved memory.
  * This is all handled in the intel-gtt.ko module. i915.ko only
- * cares about the vga bit for the vga rbiter.
+ * cares about the vga bit for the vga arbiter.
  */
 #define INTEL_GMCH_CTRL		0x52
 #define INTEL_GMCH_VGA_DISABLE  (1 << 1)