inkscape_0.48.0: add `boost` to `DEPENDS`

inkscape_0.48.0: add `boost` to `DEPENDS`

Inkscape 0.48 committed in 2dfc5b [1] seems to have a new dependency on Boost.

        | checking boost/concept_check.hpp usability... no
        | checking boost/concept_check.hpp presence... no
        | checking for boost/concept_check.hpp... no
        | configure: error: You need the boost package (e.g. libboost-dev)
        | ERROR: Function do_configure failed
        NOTE: package inkscape-0.48.0-r0: task do_configure: Failed
        ERROR: TaskFailed event exception, aborting
        ERROR: Build of /oe/openembedded/recipes/inkscape/inkscape_0.48.0.bb do_configure failed
        ERROR: Task 11 (/oe/openembedded/recipes/inkscape/inkscape_0.48.0.bb, do_configure) failed with 256
        ERROR: '/oe/openembedded/recipes/inkscape/inkscape_0.48.0.bb' failed
        ERROR: '/oe/openembedded/recipes/inkscape/inkscape_0.48.0.bb' failed
        ERROR: '/oe/openembedded/recipes/inkscape/inkscape_0.48.0.bb' failed

This patch fixes the build with `angstrom-2008.1`, `angstrom-2010.x` and `minimal` for `MACHINE = "beagleboard"`.

[1] http://cgit.openembedded.org/cgit.cgi/openembedded/commit/?id=2dfc5b7c9e0d32c3f61ff02aca2b08d22def56fc

Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: Khem Raj <raj.khem@gmail.com>