Set SOF C++ language standard to C++17 for Zephyr builds

Recent changes to Zephyr header files written in C++
use templates and features provided by the C++14 standard.
Meteorlake board that is built with Zephyr has some C++ code
that uses those headers.
We upgrade straight to C++17 since it is newest standard currently
supported by xt-clang toolchain.
This change does not affect any other boards since the do not
have any C++ code as the time of writing.

Signed-off-by: Andrey Borisovich <andrey.borisovich@intel.com>

Author: Andrey Borisovich

zephyr/CMakeLists.txt

@@ -101,6 +101,10 @@ endif()
 
 # SOF module init
 zephyr_library_named(modules_sof)
+
+# Zephyr C++ code requires 14 or newer standard
+set_property(TARGET modules_sof PROPERTY CXX_STANDARD 17)
+
 zephyr_include_directories(
 	include
 )