nrf: Update nrfx to v3.14.0 and modernize machine interfaces.

[andrewleech]

Summary

Updates the nrfx submodule from v2.0.0 (2019) to v3.14.0 and modernizes the nrf port's machine interfaces for consistency with rp2 and alif ports.

The nrfx upgrade is needed because TinyUSB's latest upstream broke its nrfx v2 code path in dcd_nrf5x.c, requiring v3+ for correct API detection. The v2-to-v3 migration touches port configuration, the startup vector table, and all peripheral drivers that call nrfx APIs directly.

While touching these drivers, the machine interfaces were brought in line with modern ports:

• Pin.irq: Rewritten to use the shared mp_irq_obj_t infrastructure (matching rp2/alif). Adds hard kwarg for soft IRQ support via mp_sched_schedule, makes handler optional, returns a proper IRQ object with flags() and trigger() methods. Boards without MICROPY_ENABLE_SCHEDULER retain the direct ISR-only path.
• SPI: init() now preserves current config when parameters aren't passed (matching rp2), instead of resetting everything to defaults.
• I2C: Added timeout kwarg (default 50ms, matching rp2/alif). Implemented using non-blocking transfers with an ISR completion callback and mp_hal_ticks_us polling loop, so the timeout is actually enforced. Also fixed TWI peripheral not being disabled on the transfer error path.
• Timer: Fixed silent regression where NRF_TIMER_FREQ_1MHz enum value (4) was interpreted as 4 Hz by the nrfx v3 config struct which now expects frequency in Hz.

All 23 nrf board configs compile clean.

Testing

Built and verified all 23 nrf board configurations (6 nRF51, 15 nRF52, 2 nRF9160). Hardware tested on nRF52840-Dongle (PCA10059) flashed via pyocd/CMSIS-DAP with the following results:

Peripheral	Result	Notes
USB CDC REPL	PASS
Pin read/write	PASS
Pin.irq	PASS	Returns <class 'irq'> object, no spurious triggers
Timer	PASS	Was broken before freq enum fix
PWM	PASS	freq and duty readback correct
SPI	PASS	init + readinto
I2C timeout	PASS	NACK on missing device: 244us/ENODEV, timeout=1us: ETIMEDOUT
ADC	PASS
RNG	PASS

Could not test successful I2C data transfer (no I2C slave device wired to the dongle). Could not hardware-test nRF51 or nRF9160 boards (no hardware), but they compile clean.

Trade-offs and Alternatives

Code size on PCA10059 increased from 252,880 to ~257,268 bytes text (+1.7%). The increase comes from nrfx v3's HALY (HAL extension) layer, atomic operations, GPIOTE channel allocator, and the mp_irq infrastructure.

Generative AI

I used generative AI tools when creating this PR, but a human has checked the code and is responsible for the code and the description above.

[github-actions]

Code size report:

Reference:  samd: Convert port to use new event waiting functions. [1f601e8]
Comparison: nrf: Add I2C timeout parameter and fix disable on error. [merge of 6228ff5]
  mpy-cross:    +0 +0.000% 
   bare-arm:    +0 +0.000% 
minimal x86:    +0 +0.000% 
   unix x64:    +0 +0.000% standard
      stm32:    +0 +0.000% PYBV10
      esp32:    +0 +0.000% ESP32_GENERIC
     mimxrt:    +0 +0.000% TEENSY40
        rp2:    +0 +0.000% RPI_PICO_W
       samd:    +0 +0.000% ADAFRUIT_ITSYBITSY_M4_EXPRESS
  qemu rv32:    +0 +0.000% VIRT_RV32