ALSA: firewire-lib/motu: use int type for the value of bitwise OR with enumerator...

ALSA: firewire-lib/motu: use int type for the value of bitwise OR with enumerator-constant

It brings some inconvenience in practice to use enumerated type for
variable to which bitwise OR with enumerator constant is assigned.

This commit replaces declarations of enumerated type with int type.

Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210518084557.102681-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>