esp32/boards: Reduce IRAM usage.

Disable unnecessary IRAM ISR functionality.

This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>

ports/esp32/boards/sdkconfig.base

@@ -99,6 +99,10 @@ CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions-4MiB.csv"
 # To reduce iRAM usage
 CONFIG_ESP32_WIFI_IRAM_OPT=n
 CONFIG_ESP32_WIFI_RX_IRAM_OPT=n
+CONFIG_SPI_MASTER_ISR_IN_IRAM=n
+CONFIG_SPI_SLAVE_ISR_IN_IRAM=n
+CONFIG_ESP_EVENT_POST_FROM_IRAM_ISR=n
+CONFIG_PERIPH_CTRL_FUNC_IN_IRAM=n
 
 # Legacy ADC Calibration Configuration
 # Only on: ESP32