FP4: Switch to defconfig fragments

Change-Id: Ieb92829fef7d77c73f9248eafcba8d7e4c91a3c7
diff --git a/BoardConfig.mk b/BoardConfig.mk
index 4a8a691..de66b32 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -96,7 +96,7 @@
 BOARD_MKBOOTIMG_ARGS += --header_version $(BOARD_BOOT_HEADER_VERSION)
 BOARD_KERNEL_IMAGE_NAME := Image
 TARGET_KERNEL_SOURCE := kernel/fairphone/sm7225
-TARGET_KERNEL_CONFIG := FP4_defconfig
+TARGET_KERNEL_CONFIG := vendor/lito-perf_defconfig vendor/debugfs.config vendor/fairphone/FP4.config
 
 # Kernel modules - Audio
 TARGET_MODULE_ALIASES += \