V4L/DVB (11242): allow v4l2 drivers to provide a get_unmapped_area handler

Shared memory mappings on nommu machines require a get_unmapped_area
file operation that suggests an address for the mapping. This patch
adds a way for v4l2 drivers to provide this callback.

Signed-off-by: Daniel Glöckner <dg@emlix.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index e36faab..2058dd4 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -40,6 +40,8 @@
 	unsigned int (*poll) (struct file *, struct poll_table_struct *);
 	long (*ioctl) (struct file *, unsigned int, unsigned long);
 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
+	unsigned long (*get_unmapped_area) (struct file *, unsigned long,
+				unsigned long, unsigned long, unsigned long);
 	int (*mmap) (struct file *, struct vm_area_struct *);
 	int (*open) (struct file *);
 	int (*release) (struct file *);