selftests: ALSA: Skip utimer test when CONFIG_SND_UTIMER is not enabled

selftests: ALSA: Skip utimer test when CONFIG_SND_UTIMER is not enabled

The timer_f.utimer test hard-fails with ASSERT_EQ when
SNDRV_TIMER_IOCTL_CREATE returns -1 on kernels without
CONFIG_SND_UTIMER. This causes the entire alsa kselftest suite to
report a failure rather than skipping the unsupported test.

When CONFIG_SND_UTIMER is not enabled, the ioctl is not recognised and
the kernel returns -ENOTTY. If the timer device or subdevice does not
exist, -ENXIO is returned. Skip the test in both cases, but still fail
on any other unexpected error.

Suggested-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/linux-kselftest/0e9c25d3-efbd-433b-9fb1-0923010101b9@stanley.mountain/
Signed-off-by: Ben Copeland <ben.copeland@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://patch.msgid.link/20260319124521.191491-1-ben.copeland@linaro.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>