tests/ports/rp2: Tune rp2.DMA test so it runs in all configurations.HEADmaster

Changes in this commit:
- Allow the DMA instance to be any instance, not just DMA(0); eg WLAN may
  be using DMA(0).
- Make the DMA timing test run a little faster by preloading `dma.active`.
- Run the DMA timing test 10 times and take the average time taken as the
  test result, to eliminate any big effects of caching.
- Change the expected time to `range(30, 80)` to cover RP2040, RP2350,
  RISC-V variants, and both bytecode and native emitter.
- Add a `sleep_ms(1)` after waiting for the IRQ to fire, so that any
  scheduled code gets a chance to run when the test is compiled with the
  native emitter.

With these changes this test passes reliably on RPI_PICO, RPI_PICO_W,
RPI_PICO2, RPI_PICO2_W, RPI_PICO2-RISCV and RPI_PICO2_W-RISCV, in both
bytecode and native emitter mode, with and without WLAN enabled.

Signed-off-by: Damien George <damien@micropython.org>

0 files changed, 0 insertions, 0 deletions