coolutil: make gst_cool_find_type public
coolutil: make gst_cool_find_type public

Change-Id: If7a040d635c8ed4db9cbeb38be6963bf5d0d3438
Reviewed-on: https://gpro.lgsvl.com/68195
Reviewed-by: Jeongseok Kim <0c03ab7a1b32f29697716389c3f9549845834271@lge.com>
Tested-by: Jeongseok Kim <0c03ab7a1b32f29697716389c3f9549845834271@lge.com>

justinjoy/gst-plugins-cool,justinjoy/gst-plugins-cool