ALSA: mpu401: Allocate resources with device-managed APIs

This patch converts the card object management with devres as a clean
up.  The remove callback gets reduced by that.

This should give no user-visible functional changes.

Note that this converts only the mpu401 card driver.  The mpu401_uart
component is still managed with snd_device.  It's for the case where
the mpu401_uart component may be removed dynamically without the
actual device unbind.

Link: https://lore.kernel.org/r/20210715075941.23332-77-tiwai@suse.de


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