kernel: add `pahole` dependency

This is needed for 5.10+ T kernel build.

Change-Id: I0729af39cad5509ea3bc8629fdf1176156be6c08

build/tasks/kernel.mk

@@ -81,6 +81,7 @@ SELINUX_DEFCONFIG := $(TARGET_KERNEL_SELINUX_CONFIG)
 
 ## Internal variables
 DTC := $(HOST_OUT_EXECUTABLES)/dtc
+PAHOLE := $(HOST_OUT_EXECUTABLES)/pahole
 KERNEL_OUT := $(TARGET_OUT_INTERMEDIATES)/KERNEL_OBJ
 RECOVERY_KERNEL_OUT := $(TARGET_OUT_INTERMEDIATES)/RECOVERY_KERNEL_OBJ
 DTBO_OUT := $(TARGET_OUT_INTERMEDIATES)/DTBO_OBJ
@@ -409,7 +410,7 @@ $(KERNEL_CONFIG): $(KERNEL_OUT) $(ALL_KERNEL_DEFCONFIG_SRCS)
 	@echo "Building Kernel Config"
 	$(call make-kernel-config,$(KERNEL_OUT),$(KERNEL_DEFCONFIG))
 
-$(TARGET_PREBUILT_INT_KERNEL): $(KERNEL_CONFIG) $(DEPMOD) $(DTC)
+$(TARGET_PREBUILT_INT_KERNEL): $(KERNEL_CONFIG) $(DEPMOD) $(DTC) $(PAHOLE)
 	@echo "Building Kernel Image ($(BOARD_KERNEL_IMAGE_NAME))"
 	$(call make-kernel-target,$(BOARD_KERNEL_IMAGE_NAME))
 	$(hide) if grep -q '^CONFIG_OF=y' $(KERNEL_CONFIG); then \
@@ -522,7 +523,7 @@ $(RECOVERY_KERNEL_CONFIG): $(ALL_RECOVERY_KERNEL_DEFCONFIG_SRCS)
 	@echo "Building Recovery Kernel Config"
 	$(call make-kernel-config,$(RECOVERY_KERNEL_OUT),$(RECOVERY_DEFCONFIG))
 
-$(TARGET_PREBUILT_INT_RECOVERY_KERNEL): $(RECOVERY_KERNEL_CONFIG) $(DEPMOD) $(DTC)
+$(TARGET_PREBUILT_INT_RECOVERY_KERNEL): $(RECOVERY_KERNEL_CONFIG) $(DEPMOD) $(DTC) $(PAHOLE)
 	@echo "Building Recovery Kernel Image ($(BOARD_KERNEL_IMAGE_NAME))"
 	$(call make-recovery-kernel-target,$(BOARD_KERNEL_IMAGE_NAME))