This patch removes some of the string registration from the
Multifunction Composite Gadget as composite layer can handle
the iManufacturer and iProduct for us.

This also adds the "needs_serial" so that composite layer will
issue a warning if user space fails to provide the iSerialNumber
module parameter.
Signed-off-by: NMichal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>