staging: sm750fb: staticize getPowerMode function

The getPowerMode function is not used outside ddk750_power, make it
static.
Signed-off-by: Mike Rapoport <mike.rapoport@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/sm750fb/ddk750_power.c

@@ -17,7 +17,7 @@ void ddk750_setDPMS(DPMS_t state)
 	}
 }
 
-unsigned int getPowerMode(void)
+static unsigned int getPowerMode(void)
 {
 	if (getChipType() == SM750LE)
 		return 0;

drivers/staging/sm750fb/ddk750_power.h

@@ -19,8 +19,6 @@ DPMS_t;
 
 void ddk750_setDPMS(DPMS_t);
 
-unsigned int getPowerMode(void);
-
 /*
  * This function sets the current power mode
  */