libiio: Bump version to 0.5

The package now offers the possibility to install Python and/or C#
bindings if the Python and Mono packages are detected.

v2: Patch generated with 'git format-patch -M' and fix indentation in libiio.mk
v3: Updated libiio.hash file

Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>