FP4: Don't declare BOARD_VENDOR

* Only matters when it differs from the device OEM.

Change-Id: Id9af8263cb42dc7a0e3a9ce8677385e224910302
diff --git a/BoardConfig.mk b/BoardConfig.mk
index d547032..a00f07e 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -7,7 +7,6 @@
 BUILD_BROKEN_DUP_RULES := true
 BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES := true
 
-BOARD_VENDOR := fairphone
 DEVICE_PATH := device/fairphone/FP4
 
 # APEX