soc: stm32f1: gpio: Fix unnecessary else statement

The bitfield determining the I/O direction already defines the pin
as either input or output, cannot be none or both at the same time

This issue was reported by Coverity

Coverity-CID: 151970

Change-Id: I18d5387139d6834004ba3269c5b54176bdc97ea7
Signed-off-by: Sergio Rodriguez <sergio.sf.rodriguez@intel.com>

arch/arm/soc/st_stm32/stm32f1/soc_gpio.c

@@ -87,8 +87,10 @@ int stm32_gpio_flags_to_conf(int flags, int *pincfg)
 	}
 
 	if (direction == GPIO_DIR_OUT) {
+		/* Pin is configured as an output */
 		*pincfg = STM32F10X_PIN_CONFIG_DRIVE_PUSH_PULL;
-	} else if (direction == GPIO_DIR_IN) {
+	} else {
+		/* Pin is configured as an input */
 		int pud = flags & GPIO_PUD_MASK;
 
 		/* pull-{up,down} maybe? */
@@ -100,8 +102,6 @@ int stm32_gpio_flags_to_conf(int flags, int *pincfg)
 			/* floating */
 			*pincfg = STM32F10X_PIN_CONFIG_BIAS_HIGH_IMPEDANCE;
 		}
-	} else {
-		return -ENOTSUP;
 	}
 
 	return 0;