Remove redundant YYLOC global declaration

gcc 10 will default to -fno-common, which causes this error at link time:

(.text+0x0): multiple definition of `yylloc’; dtc-lexer.lex.o (symbol from plugin):(.text+0x0): first defined here

This is because both dtc-lexer as well as dtc-parser define the same global symbol yyloc. Before with -fcommon those were merged into one defintion. The proper solution would be to to mark this as “extern”, however that leads to:

dtc-lexer.l:26:16: error: redundant redeclaration of ‘yylloc’ [-Werror=redundant-decls] 26 | extern YYLTYPE yylloc; | ^~~~~~ In file included from dtc-lexer.l:24: dtc-parser.tab.h:127:16: note: previous declaration of ‘yylloc’ was here 127 | extern YYLTYPE yylloc; | ^~~~~~ cc1: all warnings being treated as errors

which means the declaration is completely redundant and can just be dropped.