recipes-demo/homescreen/homescreen_git: Bump homescreen SRCREV

recipes-demo/homescreen/homescreen_git: Bump homescreen SRCREV

In order to catch up the compositor changes, specifically, to get
support for placing window's application on different outputs.

In more detail the following changes have been added:

- c9ae3bc5a1 homescreenhandler: Handle dynamic movement of windows
- 74b01c7210 homescreenhandler: Add support for starting apps on different outputs

Bug-AGL: SPEC-4529, SPEC-4673
Change-Id: I09e488ce42bdb3550a03e80c1666075c97634585
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>