Add esp32c6 support (#3234)

This PR adds support for ESP32 C6, which has been mentioned in #3208.

build-scripts/esp-idf/wamr/CMakeLists.txt

@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 # Set WAMR's build options
-if("${IDF_TARGET}" STREQUAL "esp32c3")
+if("${IDF_TARGET}" STREQUAL "esp32c3" OR "${IDF_TARGET}" STREQUAL "esp32c6")
     set(WAMR_BUILD_TARGET "RISCV32")
 else()
     set(WAMR_BUILD_TARGET "XTENSA")