package/gr-osmosdr: fix build with boost 1.7.3

package/gr-osmosdr: fix build with boost 1.7.3

boost/detail/endian.hpp has been marked as deprecated since boost 1.69.0.
This file and boost/predef/detail/endian_compat.h are no more available.

This patch suppress this header in some file, where not needed and move
to correct header and new constants. It's retrocompatible for at least all boost release > 1.69.0

[Upstream status: http://lists.osmocom.org/pipermail/osmocom-sdr/2020-June/002080.html]

Signed-off-by: Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>