package/boost: backport development branch changes to fix MIPS64 build failure

Backport from Boost/intrusive development branch. Fixes issue introduced with
version 1.80.

Issue: https://github.com/boostorg/intrusive/issues/79
Fixes: http://autobuild.buildroot.net/results/6cb/6cbc0672f3c5046405793d8cdc8f961d2ffb1d3e



Signed-off-by: Andreas Ziegler <br015@umbiko.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>