Add W5500 SPI Ethernet support for RP2040 boards using arduino-pico's
Wiznet5500lwIP class. Tested on WIZnet W5500-EVB-Pico hardware.
- Add ethernet_component_rp2040.cpp with W5500 implementation
- Add RP2040 members and setters to ethernet_component.h
- Enable RP2040 platform in SPI_SCHEMA and FILTER_SOURCE_FILES
- Add RP2040 validation, code generation, and lwIP_w5500 library
- Add W5500 RP2040 test YAML