drivers: clk: remove spinlock in clk_print_tree()

Remove spinlock handling from clk_print_tree(). This lock may mask
interrupts for a long period of time which and may affect the system
behavior. Since there is no clock unregistering and clock destroying
function, all clock references used are safe to use, even outside
the locked state. Whether or not printed information is accurate is
not an issue as clk_print_tree() is concerned as the function is only
informative.

Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Etienne Carriere <etienne.carriere@foss.st.com>

core/drivers/clk/clk.c

@@ -482,11 +482,7 @@ static void print_tree(void)
 void clk_print_tree(void)
 {
 	if (IS_ENABLED(CFG_DRIVERS_CLK_PRINT_TREE)) {
-		uint32_t exceptions = 0;
-
-		exceptions = cpu_spin_lock_xsave(&clk_lock);
-		IMSG("Clock tree summary:");
+		IMSG("Clock tree summary (informative):");
 		print_tree();
-		cpu_spin_unlock_xrestore(&clk_lock, exceptions);
 	}
 }