Pull Kconfig updates from Masahiro Yamada:

 - support -y option for merge_config.sh to avoid downgrading =y to =m

 - remove S_OTHER symbol type, and touch include/config/*.h files correctly

 - fix file name and line number in lexer warnings

 - fix memory leak when EOF is encountered in quotation

 - resolve all shift/reduce conflicts of the parser

 - warn no new line at end of file

 - make 'source' statement more strict to take only string literal

 - rewrite the lexer and remove the keyword lookup table

 - convert to SPDX License Identifier

 - compile C files independently instead of including them from zconf.y

 - fix various warnings of gconfig

 - misc cleanups

* tag 'kconfig-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
  kconfig: surround dbg_sym_flags with #ifdef DEBUG to fix gconf warning
  kconfig: split images.c out of qconf.cc/gconf.c to fix gconf warnings
  kconfig: add static qualifiers to fix gconf warnings
  kconfig: split the lexer out of zconf.y
  kconfig: split some C files out of zconf.y
  kconfig: convert to SPDX License Identifier
  kconfig: remove keyword lookup table entirely
  kconfig: update current_pos in the second lexer
  kconfig: switch to ASSIGN_VAL state in the second lexer
  kconfig: stop associating kconf_id with yylval
  kconfig: refactor end token rules
  kconfig: stop supporting '.' and '/' in unquoted words
  treewide: surround Kconfig file paths with double quotes
  microblaze: surround string default in Kconfig with double quotes
  kconfig: use T_WORD instead of T_VARIABLE for variables
  kconfig: use specific tokens instead of T_ASSIGN for assignments
  kconfig: refactor scanning and parsing "option" properties
  kconfig: use distinct tokens for type and default properties
  kconfig: remove redundant token defines
  kconfig: rename depends_list to comment_option_list
  ...