ADSP: Add /opt/analog/cces to _find_adsp_root()'s search space

This is the default install location on Linux.

Modules/Platform/ADSP-Determine.cmake

@@ -21,6 +21,9 @@ endif()
 if(NOT CMAKE_ADSP_ROOT)
   _find_adsp_root("C:/Program Files (x86)/Analog Devices/VisualDSP *")
 endif()
+if(NOT CMAKE_ADSP_ROOT)
+  _find_adsp_root("/opt/analog/cces *")
+endif()
 if(NOT IS_DIRECTORY "${CMAKE_ADSP_ROOT}")
   message(FATAL_ERROR "ADSP: could not find CCES/VDSP++ install directory ${CMAKE_ADSP_ROOT}")
 endif()