sdkconfig.p6

This replaces the original GC9A01 driver with one optimized for our
usecase, implemented directly in a brand-new BSP (board support package)
component.

The major differences between the drivers are:

 1. aware of different badge generations
 2. generic: still supporting the possibility that we might have to
    switch to a different SPI display at some point
 3. only supports writing entire screen at once from in-memory buffer:
    no line drawing, filling, etc.
 4. spi screen blitting does not waste CPU time, instead uses
    ESP-IDF/FreeRTOS DMA/Interrupt logic to perform transfers
    efficiently.

We also drive-by enable SPIRAM, as we're starting to run out of memory.