libc: arcmwdt: require static initializers

The ARC MWDT C library puts some constructors into .ctors section
to initialize its internal stdio locks. Enable the initializers
to make sure these constructors are actually executed.

Signed-off-by: Ilya Tagunov <Ilya.Tagunov@synopsys.com>

Author: tagunil

lib/libc/Kconfig

@@ -127,6 +127,7 @@ config ARCMWDT_LIBC
 	bool "ARC MWDT C library"
 	depends on !NATIVE_APPLICATION
 	depends on "$(ZEPHYR_TOOLCHAIN_VARIANT)" = "arcmwdt"
+	select STATIC_INIT_GNU
 	help
 	  C library provided by ARC MWDT toolchain.