DT510: Tier B follow-ups — GPIO DIO, CP2108, SE050 DT (B2–B4)

[ajlennon]

Parent tracking

Sub-issue of #2 (DT510 BSP bring-up plan).

Scope (Tier B — smaller blocks)

Track non-codec Tier B items that are not already covered by #3 (BQ25792).

B2 — Digital I/O (GPIO1)

• SSOT maps GPIO1 lines for digital I/O; BSP: verify no clash with existing hog / peripherals; add gpio-hog or userspace export as product requires.

B3 — CP2108 quad-UART

• Typically USB-enumerated; DT may only need reset GPIO if hardware uses one — confirm SSOT.

B4 — SE050 (I2C4 0x48)

• OpTEE / se05x stack already aligned with CFG_CORE_SE05X_I2C_BUS=3 = &i2c4 (see docs/DT510-SE050.md).
• Optional: explicit DT child under &i2c4 for kernel visibility; coordinate so TEE and kernel do not conflict.

Acceptance

• Each bullet either implemented + tested or explicitly N/A with doc note.

References

• docs/DT510-BSP-PROJECT-PLAN.md §5 Tier B

Assignees

Per parent #2: @ajlennon @ohull456