media: marvel-ccic: allow ccic and mmp drivers to coexist

Randconfig builds fail when one of the two is a built-in driver and
the other one is a loadable module:

drivers/media/platform/marvell-ccic/mcam-core.o: In function `mccic_register':
mcam-core.c:(.text+0x2594): undefined reference to `__this_module'
drivers/media/platform/marvell-ccic/mcam-core.o:(.rodata+0x50): undefined reference to `__this_module'

The problem is that mcam-core.c can not be built both ways at the smae
time. However, we can make kbuild take care of that by making the core
driver a separate module, which can be either built-in or loadable
as needed.
Making it a separate module requires exporting a few symbols and
adding the module license from the header.

Fixes: 0a9c643c ("media: marvel-ccic: re-enable mmp-driver build")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/platform/marvell-ccic/Makefile

-obj-$(CONFIG_VIDEO_CAFE_CCIC) += cafe_ccic.o
-cafe_ccic-y := cafe-driver.o mcam-core.o
-
-obj-$(CONFIG_VIDEO_MMP_CAMERA) += mmp_camera.o
-mmp_camera-y := mmp-driver.o mcam-core.o
+obj-$(CONFIG_VIDEO_CAFE_CCIC) += cafe_ccic.o mcam-core.o
+cafe_ccic-y := cafe-driver.o
 
+obj-$(CONFIG_VIDEO_MMP_CAMERA) += mmp_camera.o mcam-core.o
+mmp_camera-y := mmp-driver.o

drivers/media/platform/marvell-ccic/mcam-core.c

@@ -1720,6 +1720,7 @@ int mccic_irq(struct mcam_camera *cam, unsigned int irqs)
 	}
 	return handled;
 }
+EXPORT_SYMBOL_GPL(mccic_irq);
 
 /* ---------------------------------------------------------------------- */
 /*
@@ -1830,7 +1831,7 @@ int mccic_register(struct mcam_camera *cam)
 	v4l2_device_unregister(&cam->v4l2_dev);
 	return ret;
 }
-
+EXPORT_SYMBOL_GPL(mccic_register);
 
 void mccic_shutdown(struct mcam_camera *cam)
 {
@@ -1850,6 +1851,7 @@ void mccic_shutdown(struct mcam_camera *cam)
 	v4l2_ctrl_handler_free(&cam->ctrl_handler);
 	v4l2_device_unregister(&cam->v4l2_dev);
 }
+EXPORT_SYMBOL_GPL(mccic_shutdown);
 
 /*
  * Power management
@@ -1868,6 +1870,7 @@ void mccic_suspend(struct mcam_camera *cam)
 	}
 	mutex_unlock(&cam->s_mutex);
 }
+EXPORT_SYMBOL_GPL(mccic_suspend);
 
 int mccic_resume(struct mcam_camera *cam)
 {
@@ -1898,4 +1901,8 @@ int mccic_resume(struct mcam_camera *cam)
 	}
 	return ret;
 }
+EXPORT_SYMBOL_GPL(mccic_resume);
 #endif /* CONFIG_PM */
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");