Add support for V2 boards (CO5300 panel, CST820 touch)

[pablogfb]

Waveshare ships two incompatible revisions of the ESP32-S3-Touch-AMOLED-1.8 under the same name. Boards from around 2026-05 are V2: a CO5300 panel instead of the SH8601, and a CST820 touch controller at 0x15 instead of the FT3168 at 0x38.

The failure mode is unhelpful — a V1 build on a V2 board leaves the screen black while the firmware runs perfectly over serial, so it reads as a driver bug rather than a hardware mismatch. That's what sent me here.

Selected with -DBOARD_V2=1 via a new env:esp32-s3-amoled-v2. Defaults to V1, so existing builds are unaffected.

What changed

• Panel driver becomes Arduino_CO5300, with a column offset of 16 — the CO5300's visible 368 columns start at panel RAM column 16, and without the offset the image is shifted and wraps.
• Touch address becomes 0x15. Nothing else in touch.cpp changes: FT3168 and CST820 share the FocalTech-style register map, so the existing reads of 0x02 for finger count and 0x03..0x06 for coordinates are already correct.
• platformio.ini gains a [base] section that both envs extend.

The queued-DMA streaming path in display.cpp needed no changes at all — the CO5300 accepts the same write-continue framing (cmd 0x32, addr 0x003C00). That was the part I expected to be painful, and it just worked; the comments there were very helpful in convincing me it was safe to leave alone.

Testing

• V2: tested on hardware. Boots to [boot] imu=1 touch=1 pmu=1 rtc=1 fs=1 sd=0, menu renders correctly, touch responds, apps run.
• V1: compiles, but I have no V1 board to test on. The V1 path is unchanged from main other than moving shared settings into [base], so the risk is low — but it is untested by me, and worth a sanity check on your side before merging.

Thanks for building this — the C64 BASIC environment is a delight.