Update SPI_PORT logic for ESP32C3 and legacy ESP32 support

[gsoros]

Fix SPI_PORT selection for ESP32-C3 (and other non-classic targets) on Arduino 2.x

The existing #if ESP_ARDUINO_VERSION_MAJOR < 3 guard sets SPI_PORT to SPI2_HOST (value 1) on Arduino 2.x. However, per the ESP-IDF enumeration, SPI2_HOST = 1 maps to the SPI1 hardware bus, which is reserved for internal flash on ESP32-C3 (and C5, C6, H2, S2, S3). The correct port for these targets is value 2 (SPI3_HOST, actually SPI2 hardware) — which is what the Arduino 3.x branch already hardcodes.

This replaces the Arduino version check with a chip target check using CONFIG_IDF_TARGET_* macros, so the correct port is selected regardless of Arduino version. The original classic ESP32 code path is unchanged.