tests: posix: common: add option to build with arcmwdt libc

Add testcase to tests/posix/common with ARC MWDT libc usage.

Signed-off-by: Eugeniy Paltsev <[email protected]>
Signed-off-by: Evgeniy Paltsev <[email protected]>

Author: evgeniy-paltsev

tests/posix/common/testcase.yaml

@@ -14,6 +14,10 @@ tests:
     filter: TOOLCHAIN_HAS_NEWLIB == 1
     extra_configs:
       - CONFIG_NEWLIB_LIBC=y
+  portability.posix.common.arcmwdtlib:
+    toolchain_allow: arcmwdt
+    extra_configs:
+      - CONFIG_ARCMWDT_LIBC=y
   portability.posix.common.tls:
     platform_exclude: nsim_sem_mpu_stack_guard nsim_em_mpu_stack_guard ehl_crb
     filter: CONFIG_ARCH_HAS_THREAD_LOCAL_STORAGE and CONFIG_TOOLCHAIN_SUPPORTS_THREAD_LOCAL_STORAGE