xtensa: enable plugin support

Compiler plugins can be built starting with xtensa gcc 12. Enable plugin
support for xtensa when gcc-12 or newer is used.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/Kconfig

@@ -34,6 +34,7 @@ config XTENSA
 	select HAVE_DMA_CONTIGUOUS
 	select HAVE_EXIT_THREAD
 	select HAVE_FUNCTION_TRACER
+	select HAVE_GCC_PLUGINS if GCC_VERSION >= 120000
 	select HAVE_HW_BREAKPOINT if PERF_EVENTS
 	select HAVE_IRQ_TIME_ACCOUNTING
 	select HAVE_PCI