zephyr: lib: move cpu.c from lib-zephyr

Move zephyr cpu.c from "unnecessary" lib-zephyr to lib/zephyr.

Signed-off-by: Jaska Uimonen <jaska.uimonen@intel.com>

zephyr/CMakeLists.txt

@@ -591,13 +591,13 @@ zephyr_library_sources(
 	${SOF_SRC_PATH}/schedule/schedule.c
 
 	${SOF_SRC_PATH}/idc/zephyr_idc.c
-	${SOF_SRC_PATH}/lib-zephyr/cpu.c
 
 	# Bridge wrapper between SOF and Zephyr APIs - Will shrink over time.
 	wrapper.c
 	edf_schedule.c
 	schedule.c
 	lib/alloc.c
+	lib/cpu.c
 
 	# Common library functions - Will be moved to Zephyr over time
 	lib.c