The mixer, PCM prepare, MIDI, synth driver, and procfs callbacks are all
always invoked with IRQs enabled, so there is no point in saving the
state.

snd_emu1010_load_firmware_entry() is called from emu1010_firmware_work()
and snd_emu10k1_emu1010_init(); the latter from snd_emu10k1_create() and
snd_emu10k1_resume(), all of which have IRQs enabled.

The voice and memory functions are called from mixed contexts, so they
keep the state saving.

The low-level functions all keep the state saving, because it's not
feasible to keep track of what is called where.
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230712145750.125086-2-oswald.buddenhagen@gmx.deSigned-off-by: Takashi Iwai <tiwai@suse.de>