FP4: Set TARGET_BOOTLOADER_BOARD_NAME

* Fixes bootloader name detection in commands such as
  `fastboot flashall`

Change-Id: Ie616ca2b511ac263133842f73a63c5129f35bebe
diff --git a/BoardConfig.mk b/BoardConfig.mk
index f51e947..b579ef8 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -55,6 +55,9 @@
 # Bluetooth
 BOARD_BLUETOOTH_BDROID_BUILDCFG_INCLUDE_DIR := $(DEVICE_PATH)/bluetooth/include
 
+# Bootloader
+TARGET_BOOTLOADER_BOARD_NAME := FP4
+
 # Display
 MAX_VIRTUAL_DISPLAY_DIMENSION := 4096
 NUM_FRAMEBUFFER_SURFACE_BUFFERS := 3