Issue with AMD dependencies in prebuilt release files

[pjueon]

Hello, I've downloaded the latest release files for Windows. Upon installing it, I discovered that the CMake/clFFTTargets-release.cmake file contains references to the AMD APP SDK as follows:

set_target_properties(clFFT PROPERTIES
  IMPORTED_IMPLIB_RELEASE "${_IMPORT_PREFIX}/lib64/import/clFFT.lib"
  IMPORTED_LINK_INTERFACE_LIBRARIES_RELEASE "C:/Program Files (x86)/AMD APP SDK/2.9-1/lib/x86_64/OpenCL.lib"
  IMPORTED_LOCATION_RELEASE "${_IMPORT_PREFIX}/bin/clFFT.dll"
)

set_target_properties(StatTimer PROPERTIES
  IMPORTED_IMPLIB_RELEASE "${_IMPORT_PREFIX}/lib64/import/StatTimer.lib"
  IMPORTED_LINK_INTERFACE_LIBRARIES_RELEASE "C:/Program Files (x86)/AMD APP SDK/2.9-1/lib/x86_64/OpenCL.lib"
  IMPORTED_LOCATION_RELEASE "${_IMPORT_PREFIX}/bin/StatTimer.dll"
)

Despite having other implementations of OpenCL installed, I don't have AMD APP SDK installed (because I don't use an AMD graphics card), and this is causing errors.

While this issue doesn't arise when I build clFFT directly from the source files, I believe it would be beneficial to address this issue since many people may prefer to use prebuilt release files.