opengl: Missing link to broadcom library when building with RaspberryPi/Dispmanx support

Submitted by Alistair Buxton

Description

The majority of GL plugins were recently moved into gst-plugins-base. Subsequently, gst-plugins-bad fails to build if gst-plugins-base is built with dispmanx support.

This happens because dispmanx support requires linking bcm_host. -bad does not know about this library and so the following build error occurs:

.libs/libgstopenglmixers_la-gstopengl.o: In function plugin_init': gstopengl.c:(.text+0x10): undefined reference to bcm_host_init'
collect2: error: ld returned 1 exit status

bcm_host is added to $LIBS in -base configure.ac around line 218.

Version: 1.14.0