clk: export __clk_get_name for re-use in imx-ipu-v3 and others

This fixes the following error when building for arm-imx:
> ERROR: "__clk_get_name" [drivers/staging/imx-drm/ipu-v3/imx-ipu-v3.ko] undefined!
> make[1]: *** [__modpost] Error 1
> make: *** [modules] Error 2

There are valid usecases to get the name of a clock, be it for debugging
purposes or to register a children of a clock like done in this IPU driver.
Therefore exporting __clk_get_name() and make it available for others makes
sense.
Reported-by: Peter Robinson <pbrobinson@gmail.com>
CC: Sascha Hauer <s.hauer@pengutronix.de>
CC: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: removal of inline made redundant by 65800b2c]

drivers/clk/clk.c

@@ -263,6 +263,7 @@ const char *__clk_get_name(struct clk *clk)
 {
 	return !clk ? NULL : clk->name;
 }
+EXPORT_SYMBOL_GPL(__clk_get_name);
 
 struct clk_hw *__clk_get_hw(struct clk *clk)
 {