cmake: raise minimum required to 3.5

CMake 4.0 was released [1] which dropped compatibility with versions
older than 3.5 and causes cmake_minimum_required(3.4) to fail.
Bump the minimum required version to 3.5, which was released 9 years
ago.

[1] https://www.kitware.com/cmake-4-0-0-available-for-download/

With v4.0.0 the following build error is observed:

  |  CMake Error at CMakeLists.txt:1 (cmake_minimum_required):
  |  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.

Acked-by: Jerome Forissier <jerome.forissier@linaro.org>
Acked-by: Joakim Bech <joakim.bech@linaro.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Acked-by: Etienne Carriere <etienne.carriere@foss.st.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Author: sudeep-holla

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 3.2)
+cmake_minimum_required (VERSION 3.5)
 project (optee_examples C)
 
 # https://cmake.org/Wiki/CMake_Useful_Variables