arm-trusted-firmware: fix comment typo

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

boot/arm-trusted-firmware/arm-trusted-firmware.mk

@@ -49,7 +49,7 @@ define ARM_TRUSTED_FIRMWARE_INSTALL_IMAGES_CMDS
 	cp -dpf $(@D)/build/$(ARM_TRUSTED_FIRMWARE_PLATFORM)/release/*.bin $(BINARIES_DIR)/
 endef
 
-# Configuration ckeck
+# Configuration check
 ifeq ($(BR2_TARGET_ARM_TRUSTED_FIRMWARE)$(BR_BUILDING),yy)
 
 ifeq ($(ARM_TRUSTED_FIRMWARE_VERSION),custom)