kconfig: remove empty and unused kernel.config

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

Makefile.inc

@@ -139,8 +139,6 @@ help:
 %:
 	$(Q)$(call zephyrmake,$(O),$@)
 
-OVERLAY_CONFIG += $(ZEPHYR_BASE)/kernel/configs/kernel.config
-
 $(DOTCONFIG): $(BOARDCONFIG) $(KBUILD_DEFCONFIG_PATH) $(CONF_FILE)
 	$(Q)$(CONFIG_SHELL) $(ZEPHYR_BASE)/scripts/kconfig/merge_config.sh \
 		-q -m -O $(O) $(KBUILD_DEFCONFIG_PATH) $(OVERLAY_CONFIG) $(CONF_FILE) \

doc/tools/opensda.rst

@@ -68,7 +68,6 @@ application to flash.
      $ make OPENSDA_FW=daplink flash
      Using /home/maureen/zephyr/boards/arm/frdm_k64f/frdm_k64f_defconfig as base
      Merging /home/maureen/zephyr/tests/include/test.config
-     Merging /home/maureen/zephyr/kernel/configs/kernel.config
      Merging prj.conf
      #
      # configuration written to .config
@@ -140,7 +139,6 @@ program your Zephyr application to flash. It will leave you at a gdb prompt.
      $ make OPENSDA_FW=daplink debug
      Using /home/maureen/zephyr/boards/arm/frdm_k64f/frdm_k64f_defconfig as base
      Merging /home/maureen/zephyr/tests/include/test.config
-     Merging /home/maureen/zephyr/kernel/configs/kernel.config
      Merging prj.conf
      #
      # configuration written to .config
@@ -264,7 +262,6 @@ program your Zephyr application to flash. It will leave you at a gdb prompt.
      $ make OPENSDA_FW=jlink debug
      Using /home/maureen/zephyr/boards/arm/frdm_k64f/frdm_k64f_defconfig as base
      Merging /home/maureen/zephyr/tests/include/test.config
-     Merging /home/maureen/zephyr/kernel/configs/kernel.config
      Merging prj.conf
      #
      # configuration written to .config

kernel/configs/kernel.config

@@ -1,2 +0,0 @@
-# empty for now, use this file for global kernel configurations and overrides.
-#