RTL-SDR device support for SoapySDR (default version)

 The Soapy RTL-SDR project provides a SoapySDR hardware support module.
 Using this, any program using SoapySDR to interface to software
 defined radio hardware can make use of low cost DVB-T/DAB+ USB dongles
 based on the Realtek RTL2832U chip as receivers.
 .
 This is an empty dependency package that pulls in the RTL-SDR module
 for the default version of libsoapysdr.