ASoC: SOF: Drop obsolete dependency on COMPILE_TEST

Since commit 0166dc11

 ("of: make CONFIG_OF user selectable"), it
is possible to test-build any driver which depends on OF on any
architecture by explicitly selecting OF. Therefore depending on
COMPILE_TEST as an alternative is no longer needed.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Link: https://lore.kernel.org/r/20221127193549.211bf8f7@endymion.delvare
Signed-off-by: Mark Brown <broonie@kernel.org>