ALSA: gus: Allocate resources with device-managed APIs

This patch converts the resource management in ISA gus drivers with
devres as a clean up.  Each manual resource management is converted
with the corresponding devres helper.  The remove callback became
superfluous and dropped.

This should give no user-visible functional changes.

Link: https://lore.kernel.org/r/20210715075941.23332-66-tiwai@suse.de


Signed-off-by: Takashi Iwai <tiwai@suse.de>