espressif: Add ESP32-C3 initial basic support

ESP32-C3 target added to the Espressif port, CMakeLists, and
added related files to ESP32-C3 target directory as well.

Signed-off-by: Almir Okato <almir.okato@espressif.com>
diff --git a/boot/espressif/hal/include/esp32c3/sdkconfig.h b/boot/espressif/hal/include/esp32c3/sdkconfig.h
new file mode 100644
index 0000000..06f60ae
--- /dev/null
+++ b/boot/espressif/hal/include/esp32c3/sdkconfig.h
@@ -0,0 +1,9 @@
+#define CONFIG_IDF_TARGET_ESP32C3 1
+#define CONFIG_IDF_TARGET_ARCH_RISCV 1
+#define CONFIG_SPI_FLASH_ROM_DRIVER_PATCH 1
+#define CONFIG_MCUBOOT 1
+#define NDEBUG 1
+#define CONFIG_BOOTLOADER_WDT_TIME_MS 9000
+#define CONFIG_ESP_CONSOLE_UART_BAUDRATE 115200
+#define CONFIG_BOOTLOADER_OFFSET_IN_FLASH 0x0000
+#define BOOTLOADER_BUILD 1