Add -lvchostif to link when using -lEGL on rpi

This is required because libEGL from userland uses sybols
from this library.

lib/libEGL.so.1.0.0                                                                                                                                                                                                                              121: 00000000     0 FUNC    GLOBAL DEFAULT  UND vc_dispmanx_element_add
  1552: 00000000     0 FUNC    GLOBAL DEFAULT  UND vc_dispmanx_element_add

These symbols are provided by libvchostif as seen below

lib/libvchostif.so
   252: 0000b161   192 FUNC    GLOBAL DEFAULT    9 vc_dispmanx_element_add
   809: 0000b161   192 FUNC    GLOBAL DEFAULT    9 vc_dispmanx_element_add

With this explicit link, plugins fail during runtime

(gst-plugin-scanner:571): GStreamer-WARNING **: Failed to load plugin '/usr/lib/gstreamer-1.0/libgstomx.so': Error relocating /usr/lib/libgstgl-1.0.so.0: vc_dispmanx_element_add: symbol not found
(gst-plugin-scanner:571): GStreamer-WARNING **: Failed to load plugin '/usr/lib/gstreamer-1.0/libgstopengl.so': Error relocating /usr/lib/libgstgl-1.0.so.0: vc_dispmanx_element_add: symbol not found

Signed-off-by: Khem Raj <raj.khem@gmail.com>

Upstream-Status: Pending
Index: gst-plugins-bad-1.10.4/configure.ac
===================================================================
--- gst-plugins-bad-1.10.4.orig/configure.ac
+++ gst-plugins-bad-1.10.4/configure.ac
@@ -785,7 +785,7 @@ case $host in
                             HAVE_EGL=yes
                             HAVE_GLES2=yes
                             HAVE_EGL_RPI=yes
-                            EGL_LIBS="-lbcm_host -lvcos -lvchiq_arm"
+                            EGL_LIBS="-lbcm_host -lvchostif -lvcos -lvchiq_arm"
                             EGL_CFLAGS=""
                             AC_DEFINE(USE_EGL_RPI, [1], [Use RPi platform])
                           ])