bare/qemu: Fixes building on FreeBSD

- Move the qemu config to a common file shared by qemu and qemu4.

- Disable nettle on qemu4, FreeBSd complained.

- Add some extra git cleaning steps to the git path. These however
  do not full clean the qemu submodules and it is not worth the
  effort to try and fix.

- The devel/qemu will not build on machines with python set to
  python3. This will not be fixed, use qemu4.

Closes #3966

bare/config/bare-config.cfg

@@ -4,8 +4,6 @@
 
 #
 # The RTEMS http git URL.
-#
-%define rtems_version         4.12
 %define rtems_http_git        http://git.rtems.org
 %define rtems_git_tools       %{rtems_http_git}/rtems-tools/plain/tools/%{rtems_version}
 %define bare_binutils_patches %{rtems_git_tools}/binutils

bare/config/devel/pixman-0.32.4-1.cfg

@@ -8,7 +8,7 @@
 
 %include %{_configdir}/base.cfg
 
-%define pixman_version 0.32.4
+%define pixman_version 0.40.0
 %hash sha256 pixman-0.32.4.tar.gz 80c7ed420e8a3ae749800241e6347c3d55681296cab71384be7969cd9e657e84
 
 #

bare/config/devel/qemu-git-1.cfg

@@ -23,7 +23,7 @@
 %if %{rsb_released} && %{!defined without_release_url}
  %source set qemu %{rtems_release_url}/%{rtems_version}/sources/qemu-git-42d58e7.tar.xz
 %else
- %source set qemu git://git.qemu-project.org/qemu.git?pull?checkout=%{qemu_version}?submodule=dtc
+ %source set qemu git://git.qemu-project.org/qemu.git?clean=force?pull?checkout=%{qemu_version}?submodule=dtc
 %endif
 
 #