package/xserver_xorg-server: add version 1.17.4

package/xserver_xorg-server: add version 1.17.4

Some old binary blobs drivers only implement an old VIDEODRV ABI. This
is the case for the AMD Catalyst driver for example.

Such a situation already exists with the nvidia-tegra23, that only
support the VIDEODRV ABI 14.

Since VIDEODRV ABIs are not backward compatible [0], lets introduce an
older Xserver version that supports such an old ABI.

0. https://www.x.org/wiki/XorgModuleABIVersions/

Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>