gst-plugins-ugly: Fix opencore AMR plugin support

opencore 0.1.3 and later use a different header installation path.
Fix the gst-plugins-ugly AMR plugin to use the correct paths, and add
packageconfigs for amrwb and amrnb.

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>