soc: actions: include header to fix missing prototype

Include the header with prototype of owl_sps_set_pg to fix:

  drivers/soc/actions/owl-sps-helper.c:16:5: warning: no previous prototype for 'owl_sps_set_pg' [-Wmissing-prototypes]
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

drivers/soc/actions/owl-sps-helper.c

@@ -10,6 +10,7 @@
 
 #include <linux/delay.h>
 #include <linux/io.h>
+#include <linux/soc/actions/owl-sps.h>
 
 #define OWL_SPS_PG_CTL	0x0