xmlto: Update to use upstream tip of trunk

xmlto: Update to use upstream tip of trunk

There are several fixes which are done to fix builds with newer
compilers after 0.0.28 was releases in 2015 a long time ago.

Add a patch to fix manpages builds not trying to access network during
build

Add UPSTREAM_CHECK_COMMITS = "1"

Regenerate xmlif from lex files, before configuring the build.
Run lex from sourcedir to avoid emitting absolute source paths via #line
directive into generated c source file which ends up causing
reproducability isssue

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>