ALSA: core: add kunitconfig

It is helpful to add .kunitconfig if we work with the tools provided by
KUnit project. The file describes the series of kernel configurations to
satisfy the dependency to build the target test.

For example:

$ ./tools/testing/kunit/kunit.py run --arch=arm64 --cross_compile=aarch64-linux-gnu- --kunitconfig=sound/core/
[11:35:13] Configuring KUnit Kernel ...
Regenerating .config ...
Populating config with:
$ make ARCH=arm64 O=.kunit olddefconfig CROSS_COMPILE=aarch64-linux-gnu-
[11:35:19] Building KUnit Kernel ...
Populating config with:
$ make ARCH=arm64 O=.kunit olddefconfig CROSS_COMPILE=aarch64-linux-gnu-
Building with:
$ make ARCH=arm64 O=.kunit --jobs=8 CROSS_COMPILE=aarch64-linux-gnu-
[11:37:35] Starting KUnit Kernel (1/1)...
[11:37:35] ============================================================
Running tests with:
$ qemu-system-aarch64 -nodefaults -m 1024 -kernel .kunit/arch/arm64/boot/Image.gz -append 'kunit.enable=1 console=ttyAMA0 kunit_shutdown=reboot' -no-reboot -nographic -serial stdio -machine virt -cpu max,pauth-impdef=on
[11:37:35] ============== sound-core-test (10 subtests) ===============
[11:37:35] [PASSED] test_phys_format_size
[11:37:35] [PASSED] test_format_width
[11:37:35] [PASSED] test_format_endianness
[11:37:35] [PASSED] test_format_signed
[11:37:35] [PASSED] test_format_fill_silence
[11:37:35] [PASSED] test_playback_avail
[11:37:35] [PASSED] test_capture_avail
[11:37:35] [PASSED] test_card_set_id
[11:37:35] [PASSED] test_pcm_format_name
[11:37:35] [PASSED] test_card_add_component
[11:37:35] ================= [PASSED] sound-core-test =================
[11:37:35] ============================================================
[11:37:35] Testing complete. Ran 10 tests: passed: 10
[11:37:35] Elapsed time: 142.333s total, 5.617s configuring, 136.047s building, 0.630s running

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Message-ID: <20240317024050.588370-1-o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>