drm/i915/i915_gem: Provide function names to complete the expected kerneldoc format

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/i915/i915_gem.c:447: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 drivers/gpu/drm/i915/i915_gem.c:536: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 drivers/gpu/drm/i915/i915_gem.c:726: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 drivers/gpu/drm/i915/i915_gem.c:811: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Eric Anholt <eric@anholt.net>
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
[Jani: fix i915_gem_sw_finish_ioctl while applying]
Link: https://patchwork.freedesktop.org/patch/msgid/20230331092607.700644-15-lee@kernel.org

drivers/gpu/drm/i915/i915_gem.c

@@ -444,7 +444,7 @@ i915_gem_gtt_pread(struct drm_i915_gem_object *obj,
 }
 
 /**
- * Reads data from the object referenced by handle.
+ * i915_gem_pread_ioctl - Reads data from the object referenced by handle.
  * @dev: drm device pointer
  * @data: ioctl data blob
  * @file: drm file pointer
@@ -533,7 +533,7 @@ ggtt_write(struct io_mapping *mapping,
 }
 
 /**
- * This is the fast pwrite path, where we copy the data directly from the
+ * i915_gem_gtt_pwrite_fast - This is the fast pwrite path, where we copy the data directly from the
  * user into the GTT, uncached.
  * @obj: i915 GEM object
  * @args: pwrite arguments structure
@@ -723,7 +723,7 @@ i915_gem_shmem_pwrite(struct drm_i915_gem_object *obj,
 }
 
 /**
- * Writes data to the object referenced by handle.
+ * i915_gem_pwrite_ioctl - Writes data to the object referenced by handle.
  * @dev: drm device
  * @data: ioctl data blob
  * @file: drm file
@@ -808,7 +808,7 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
 }
 
 /**
- * Called when user space has done writes to this buffer
+ * i915_gem_sw_finish_ioctl - Called when user space has done writes to this buffer
  * @dev: drm device
  * @data: ioctl data blob
  * @file: drm file