kconfig: re-sync with Linux 4.10

Re-sync all files under the scripts/kconfig directory with
Linux 4.10.

Some parts include U-Boot own modification.  I made sure to not
revert the following commits:

 5b8031ccb4ed ("Add more SPDX-License-Identifier tags")
 192bc6948b02 ("Fix GCC format-security errors and convert sprintfs.")
 da58dec86616 ("Various Makefiles: Add SPDX-License-Identifier tags")
 20c20826efab ("Kconfig: Enable usage of escape char '\' in string values")

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/scripts/kconfig/zconf.gperf b/scripts/kconfig/zconf.gperf
index b6ac02d..ead02ed 100644
--- a/scripts/kconfig/zconf.gperf
+++ b/scripts/kconfig/zconf.gperf
@@ -22,6 +22,7 @@
 config,		T_CONFIG,	TF_COMMAND
 menuconfig,	T_MENUCONFIG,	TF_COMMAND
 help,		T_HELP,		TF_COMMAND
+---help---,	T_HELP,		TF_COMMAND
 if,		T_IF,		TF_COMMAND|TF_PARAM
 endif,		T_ENDIF,	TF_COMMAND
 depends,	T_DEPENDS,	TF_COMMAND
@@ -37,6 +38,7 @@
 hex,		T_TYPE,		TF_COMMAND, S_HEX
 string,		T_TYPE,		TF_COMMAND, S_STRING
 select,		T_SELECT,	TF_COMMAND
+imply,		T_IMPLY,	TF_COMMAND
 range,		T_RANGE,	TF_COMMAND
 visible,	T_VISIBLE,	TF_COMMAND
 option,		T_OPTION,	TF_COMMAND