Fix no audio on cold boot for rk817 clone boards (force Playback Path re-program)

[kico1603]

Problem

On a cold boot there is no audio (speaker or headphones, menu or emulators) on rk817 clone boards. A suspend/resume is currently the only workaround, and it lasts until the next cold boot.

• Board (/proc/cpuinfo Hardware): G80CA-MB V1.3-20251212 Panel 8, variant clone
• Codec: rockchip,rk817-codec (card 0, ff070000.i2s-rk817-hifi), ALSA only

Root cause

r36_config.sh sets the output path on every boot with:

amixer -c 0 cset iface=MIXER,name='Playback Path' "$CUR_ALSA_PATH"   # SPK_HP

But these boards power up with Playback Path already at SPK_HP, so writing the same value is a no-op: the codec's output route is never (re)programmed and it stays silent until a suspend/resume forces a re-sync. amixer contents on a silent cold boot shows everything already looks correct, yet there is no sound:

numid=1 'Playback Path' items: OFF/SPK/HP/SPK_HP : values=3  (SPK_HP)
numid=3 'Playback Volume' 0..237                 : 232,232
numid=5 'Headphone Jack'                          : off

alsa-restore.service already runs alsactl restore at boot, so a plain state restore is not enough — what fixes it on resume is the codec being forced to reprogram the route.

Fix

Force a real transition (OFF -> target) before the target path, so the driver actually reprograms/enables the output route.

Testing

On my G80CA-MB V1.3 (clone) unit, cold boot was silent until a suspend/resume. Running exactly this forced OFF -> SPK_HP transition restores speaker output on cold boot (verified on-device). It is harmless on boards that don't have the bug — it just re-asserts the same path.

Note: my on-device verification ran the toggle shortly after boot; here it is folded into r36_config.sh. The mechanism (updating the route before EmulationStation opens the PCM) should be equivalent. Happy to gate it to variant = clone or adjust placement/timing if you prefer.

Scope

Likely affects other rk817 clone boards, not just G80CA-MB V1.3.

[HunterSoul5]

This looks related to the audio issue I ran into on my board (Y3506_V04_20250523,
aftermarket Panel 5 / HL-MP35HD-B-V5) — simultaneous SPK+HP output from a DTB
mismatch, also involving an rk817 clone codec.

I opened #195 with scripts (audio-hp.sh / audio-speaker.sh / audio-toggle.sh)
that force-reprogram the Playback Path via amixer and persist the choice with
alsactl store, so it's restored correctly on the next boot/resume. Might be
useful as a reference or complement to the cold-boot fix here — happy to test
together if it helps.