drm/vc4: Fix comment in vc4_drv.h

Fixes a copy&paste error.

Signed-off-by: Boris Brezillon <[e-mail]>
Reviewed-by: Eric Anholt <[e-mail]>
Link: http://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/vc4/vc4_drv.h

···
 extern struct platform_driver vc4_hdmi_driver;
 int vc4_hdmi_debugfs_regs(struct seq_file *m, void *unused);
 
-/* vc4_hdmi.c */
+/* vc4_vec.c */
 extern struct platform_driver vc4_vec_driver;
 int vc4_vec_debugfs_regs(struct seq_file *m, void *unused);