perl: replace a patch with a config option

perl: replace a patch with a config option

Instead of patching in LDFLAGS into makefiles, simply
append them to 'lddlflags' (perl's keyword for 'linker flags').

See here for upstream discussions:
https://github.com/Perl-Toolchain-Gang/ExtUtils-MakeMaker/pull/406
https://github.com/arsv/perl-cross/pull/124

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>