gpu:drm: Fix typo in Documentation/DocBook/drm.xml

This patch fix spelling typos found in drm.xml.
It is because the file is generated from comments in
source codes, I have to fix the typos within source files.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 78ca308..6872eca 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -328,7 +328,7 @@
  */
 
 /**
- * drm_gem_prime_export - helper library implemention of the export callback
+ * drm_gem_prime_export - helper library implementation of the export callback
  * @dev: drm_device to export from
  * @obj: GEM object to export
  * @flags: flags like DRM_CLOEXEC
@@ -483,7 +483,7 @@
 EXPORT_SYMBOL(drm_gem_prime_handle_to_fd);
 
 /**
- * drm_gem_prime_import - helper library implemention of the import callback
+ * drm_gem_prime_import - helper library implementation of the import callback
  * @dev: drm_device to import into
  * @dma_buf: dma-buf object to import
  *