[jerryscript] Rebase to latest JerryScript (#1818)

JerryScript updated cmake on how to build with external toolchains;
this patch will fix the breakage.

Signed-off-by: Jimmy Huang <[email protected]>

Author: Jimmy Huang

cmake/jerry.cmake

@@ -30,11 +30,11 @@ endif()
 set(CMAKE_ARGS
   -B${JERRY_LIBDIR}
   -DCMAKE_BUILD_TYPE=MinSizeRel
-  -DCMAKE_TOOLCHAIN_FILE=${JERRY_BASE}/cmake/toolchain_external.cmake
+  -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
+  -DCMAKE_C_COMPILER_WORKS=TRUE
+  -DCMAKE_SYSTEM_NAME=Zephyr
   -DENABLE_ALL_IN_ONE=${ALL_IN_ONE}
   -DENABLE_LTO=OFF
-  -DEXTERNAL_CMAKE_C_COMPILER=${CMAKE_C_COMPILER}
-  -DEXTERNAL_CMAKE_C_COMPILER_ID=GNU
   -DEXTERNAL_COMPILE_FLAGS=${external_project_cflags}
   -DFEATURE_ERROR_MESSAGES=ON
   -DFEATURE_INIT_FINI=ON