mfd: Refactor db8500-prcmu request_clock() function

This refactors the mfd/dbx500-prcmu drivers to use a switch()
statement rather than nested if/else-construction.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/db8500-prcmu.c

@@ -1433,17 +1433,20 @@ static int request_sga_clock(u8 clock, bool enable)
  */
 int db8500_prcmu_request_clock(u8 clock, bool enable)
 {
-	if (clock == PRCMU_SGACLK)
+	switch(clock) {
+	case PRCMU_SGACLK:
 		return request_sga_clock(clock, enable);
-	else if (clock < PRCMU_NUM_REG_CLOCKS)
-		return request_reg_clock(clock, enable);
-	else if (clock == PRCMU_TIMCLK)
+	case PRCMU_TIMCLK:
 		return request_timclk(enable);
-	else if (clock == PRCMU_SYSCLK)
+	case PRCMU_SYSCLK:
 		return request_sysclk(enable);
-	else if (clock == PRCMU_PLLSOC1)
+	case PRCMU_PLLSOC1:
 		return request_pll(clock, enable);
-	else
+	default:
+		break;
+	}
+	if (clock < PRCMU_NUM_REG_CLOCKS)
+		return request_reg_clock(clock, enable);
 	return -EINVAL;
 }