configure: disable lex/yacc on Solaris

It currently breaks, disable it until we can figure it out:

   LEX lex.yy.c
"exp/expression-parser.l":line 166: Warning: Non-portable Character Class
  YACC y.tab.c
    CC lex.yy.o
exp/expression-parser.l:43:37: error: conflicting types for ‘yyunput’
lex.yy.c:31:7: note: previous declaration of ‘yyunput’ was here
exp/expression-parser.l:44:46: error: macro "input" passed 1 arguments, but takes just 0
exp/expression-parser.l: In function ‘yylex’:
exp/expression-parser.l:61:1: warning: label ‘yyfussy’ defined but not used
exp/expression-parser.l:54:22: warning: unused variable ‘yyprevious’
exp/expression-parser.l: At top level:
exp/expression-parser.l:297:1: warning: missing braces around initializer
exp/expression-parser.l:297:1: warning: (near initialization for ‘yycrank[0]’)
exp/expression-parser.l:376:1: warning: missing braces around initializer
exp/expression-parser.l:376:1: warning: (near initialization for ‘yysvec[0]’)
exp/expression-parser.l:714:6: error: conflicting types for ‘yyunput’
exp/expression-parser.l:43:37: note: previous declaration of ‘yyunput’ was here
make: *** [lex.yy.o] Error 1

Signed-off-by: Jens Axboe <axboe@fb.com>
Merge branch 'master' of ssh://git.kernel.dk/data/git/fio