MISC: convert drivers/misc/* to use module_platform_driver()

This patch converts the drivers in drivers/misc/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Ira W. Snyder <iws@ovro.caltech.edu>
Cc: Pavan Savoy <pavan_savoy@ti.com>
Cc: Donggeun Kim <dg77.kim@samsung.com>
Acked-By: Pratyush Anand <pratyush.anand@st.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Pratyush Anand <pratyush.anand@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>