boot/zephyr: cleanup GPIO pin setup

Removed configuration of gpio pin using flags which were
removed for zephyr-project long ago. Also old method of read
the pin value was removed.
No sense to keep that as nowadays MCUboot is also not compatible
with zephyr version which supports these flags and methods.

Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>

Author: nvlsianpu

boot/zephyr/main.c

@@ -380,20 +380,12 @@ static bool detect_pin(const char* port, int pin, uint32_t expected, int delay)
      * use the raw interface.
      */
     rc = gpio_pin_configure(detect_port, pin,
-#ifdef GPIO_INPUT
-                            GPIO_INPUT | GPIO_PULL_UP
-#else
-                            GPIO_DIR_IN | GPIO_PUD_PULL_UP
-#endif
-           );
+                            GPIO_INPUT | GPIO_PULL_UP);
     __ASSERT(rc == 0, "Failed to initialize boot detect pin.\n");
 
-#ifdef GPIO_INPUT
     rc = gpio_pin_get_raw(detect_port, pin);
     detect_value = rc;
-#else
-    rc = gpio_pin_read(detect_port, pin, &detect_value);
-#endif
+
     __ASSERT(rc >= 0, "Failed to read boot detect pin.\n");
 
     if (detect_value == expected) {
@@ -404,12 +396,8 @@ static bool detect_pin(const char* port, int pin, uint32_t expected, int delay)
             int64_t timestamp = k_uptime_get();
 
             for(;;) {
-#ifdef GPIO_INPUT
                 rc = gpio_pin_get_raw(detect_port, pin);
                 detect_value = rc;
-#else
-                rc = gpio_pin_read(detect_port, pin, &detect_value);
-#endif
                 __ASSERT(rc >= 0, "Failed to read boot detect pin.\n");
 
                 /* Get delta from when this started */