mkbp: change preprocess Kconfig to IS_ENABLED

Clean up CL for https://crrev.com/c/4597039.

BUG=b:286038072
TEST=OS can get EC MKBP event.

Change-Id: I945c92d37758e298465888b93518d46524438073
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/4598637
Reviewed-by: Jonathon Murphy <[email protected]>
Commit-Queue: Eric Lai <[email protected]>
Code-Coverage: Eric Lai <[email protected]>
Auto-Submit: Eric Lai <[email protected]>
Tested-by: Eric Lai <[email protected]>

Author: Eric Lai

common/mkbp_event.c

@@ -104,11 +104,12 @@ static int mkbp_set_host_active_via_gpio(int active, uint32_t *timestamp)
 		lock_key = irq_lock();
 		*timestamp = __hw_clock_source_read();
 	}
-#if defined CONFIG_MKBP_USE_GPIO_ACTIVE_HIGH
-	gpio_set_level(GPIO_EC_INT_L, active);
-#else
-	gpio_set_level(GPIO_EC_INT_L, !active);
-#endif
+
+	if (IS_ENABLED(CONFIG_MKBP_USE_GPIO_ACTIVE_HIGH))
+		gpio_set_level(GPIO_EC_INT_L, active);
+	else
+		gpio_set_level(GPIO_EC_INT_L, !active);
+
 	if (timestamp)
 		irq_unlock(lock_key);