ALSA: core: add isascii() check to card ID generator

The card identifier should contain only safe ASCII characters. The isalnum()
returns true also for characters for non-ASCII characters.

Link: pipewire/pipewire#4135
Link: https://lore.kernel.org/linux-sound/yk3WTvKkwheOon_LzZlJ43PPInz6byYfBzpKkbasww1yzuiMRqn7n6Y8vZcXB-xwFCu_vb8hoNjv7DTNwH5TWjpEuiVsyn9HPCEXqwF4120=@protonmail.com/


Cc: stable@vger.kernel.org
Reported-by: Barnabás Pőcze <pobrn@protonmail.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Link: https://patch.msgid.link/20241002194649.1944696-1-perex@perex.cz


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