Expanded Rust Zephyr device support

[d3zd3z]

Adding device support for Zephyr involves the following:

• Analyzing the API for the device.
• Determine what DT nodes are appropriate, and extending the DT generator for these.
• Writing a blocking API that generally fairly directly calls the driver. This is provided the
  device provides a blocking API.
• Writing an async API. This will depend on how the async interface works for this device.

For some devices, it might make sense to add Zephyr rtio support to that device, so that the
existing RTIO support can be used to leverage adding async operations to that driver.

Some areas this might make sense to do:

• Clock Control
• Comparator
• DMA (depending on whether this is usable by itself, or just part of other drivers)
• eeprom
• haptics
• led_strip
• pwm
• regulator
• rtc
• stepper