ALSA: more section mismatches

Fix section mismatch warnings:

WARNING: sound/built-in.o(.exit.text+0x3ad): Section mismatch: reference to .init.text: (between 'sb_exit' and 'unload_uart6850')
WARNING: sound/built-in.o(.exit.text+0x753): Section mismatch: reference to .init.text: (between 'snd_mts64_module_exit' and 'snd_portman_module_exit')

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>