drm: Fix for kernel doc warning

Added colon in kernel-doc comment to fix the warning.

./include/drm/drm_drv.h:372: warning: Incorrect use of kernel-doc format:          * @fbdev_probe
./include/drm/drm_drv.h:435: warning: Function parameter or struct member 'fbdev_probe' not described in 'drm_driver'

Signed-off-by: R Sundar <prosunofficial@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241003023806.17537-1-prosunofficial@gmail.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

include/drm/drm_drv.h

@@ -369,7 +369,7 @@ struct drm_driver {
 			       uint64_t *offset);
 
 	/**
-	 * @fbdev_probe
+	 * @fbdev_probe:
 	 *
 	 * Allocates and initialize the fb_info structure for fbdev emulation.
 	 * Furthermore it also needs to allocate the DRM framebuffer used to