trusted-firmware-a: fix project name spelling

The version string generated for ARM Trusted-Firmware-A was stated as
"OpenWRT". Fix that by changing it to the exact spelling "OpenWrt"

Signed-off-by: Daniel Golle <[email protected]>

include/trusted-firmware-a.mk

@@ -74,7 +74,7 @@ define Build/Compile/Trusted-Firmware-A
 		CROSS_COMPILE=$(TARGET_CROSS) \
 		OPENSSL_DIR=$(STAGING_DIR_HOST) \
 		PLAT=$(PLAT) \
-		BUILD_STRING="OpenWRT v$(PKG_VERSION)-$(PKG_RELEASE) ($(VARIANT))" \
+		BUILD_STRING="OpenWrt v$(PKG_VERSION)-$(PKG_RELEASE) ($(VARIANT))" \
 		$(TFA_MAKE_FLAGS)
 endef