Fix configuration with cmake >= 4:

Compatibility with CMake < 3.5 has been removed from CMake.

Update the VERSION argument <min> value.  Or, use the <min>...<max> syntax
to tell CMake that the project requires at least <min> but has been updated
to work with policies introduced by <max> or earlier.

Or, add -DCMAKE_POLICY_VERSION_MINIMUM=3.5 to try configuring anyway.

https://github.com/pothosware/SoapyRTLSDR/issues/81
https://github.com/pothosware/SoapyRTLSDR/commit/bb2d1511b957138051764c9193a3d6971e912b85
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -1,7 +1,7 @@
 ########################################################################
 # Build Soapy SDR support module for RTL-SDR Devices
 ########################################################################
-cmake_minimum_required(VERSION 2.8.12)
+cmake_minimum_required(VERSION 2.8.12...3.10)
 project(SoapyRTLSDR CXX)
 
 find_package(SoapySDR "0.4.0" NO_MODULE REQUIRED)