fix “make kernelconfig” (2 things):

• patch from wbx to have it copied from/to the correct directory
• honour HOSTCC, HOSTCFLAGS

Signed-off-by: Thorsten Glaser <tg@mirbsd.org>

mk/build.mk

@@ -191,9 +191,9 @@ switch:
 	fi
 
 kernelconfig:
-	cp $(TOPDIR)/target/$(ARCH)/kernel.config $(BUILD_DIR)/linux/.config
-	$(MAKE) -C $(BUILD_DIR)/linux/ ARCH=$(ARCH) menuconfig
-	cp $(BUILD_DIR)/linux/.config $(TOPDIR)/target/$(ARCH)/kernel.config
+	cp $(TOPDIR)/target/$(ADK_TARGET_ARCH)/kernel.config $(BUILD_DIR)/linux/.config
+	${KERNEL_MAKE_ENV} ${MAKE} ${KERNEL_MAKE_OPTS} -C $(BUILD_DIR)/linux menuconfig
+	cp $(BUILD_DIR)/linux/.config $(TOPDIR)/target/$(ADK_TARGET_ARCH)/kernel.config
 
 # create a new package from package/.template
 newpackage: