flex: remove obsolete disable-tests.patch

We added this because automake was causing things to be built, but now
this doesn't seem to be the case:

  all: all-am

  all-am: Makefile $(SCRIPTS)

  SCRIPTS = $(dist_noinst_SCRIPTS)

  dist_noinst_SCRIPTS = tableopts.sh

tableopts.sh is a source file that is both in the tarballs and git.

Thus, remove the patch.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

Author: rossburton

meta/recipes-devtools/flex/flex/disable-tests.patch

@@ -15,7 +15,6 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=e4742cf92e89040b39486a6219b68067 \
 SRC_URI = "${GITHUB_BASE_URI}/download/v${PV}/flex-${PV}.tar.gz \
            file://run-ptest \
            file://0001-tests-add-a-target-for-building-tests-without-runnin.patch \
-           ${@bb.utils.contains('PTEST_ENABLED', '1', '', 'file://disable-tests.patch', d)} \
            file://0001-build-AC_USE_SYSTEM_EXTENSIONS-in-configure.ac.patch \
            file://check-funcs.patch \
            file://0001-Emit-no-line-directives-if-gen_line_dirs-is-false.patch \