raspberrypi: build graphic drivers from sources

Use userland recipe instead of binary-only vc-graphics.

Change-Id: I6d26e61a4caf083ccb2abc9aa969c1db956a6a3c
Reviewed-by: Samuli Piippo <samuli.piippo@digia.com>

conf/distro/include/raspberrypi.conf

 IMAGE_FSTYPES = "tar.gz ext3 rpi-sdimg"
 
-PREFERRED_PROVIDER_virtual/libgles1 = "vc-graphics"
-PREFERRED_PROVIDER_virtual/libgl = "vc-graphics"
+PREFERRED_PROVIDER_virtual/libgles1 = "userland"
+PREFERRED_PROVIDER_virtual/libgl = "userland"
 
 MACHINE_EXTRA_INSTALL = "\
-        vc-graphics \
+        userland \
         "
 
 MACHINE_EXTRA_INSTALL_SDK = " \
-        vc-graphics-dev \
+        userland-dev \
         "