SWDEV-414828 - set AMD_DK_ROOT variable to env DK_ROOT

this ensures python to be picked from DK

Change-Id: Idd006b7a2bb819c6aa747136aa55cfc28737a5a9

rocclr/cmake/ROCclrPAL.cmake

@@ -23,6 +23,7 @@ set(PAL_CLIENT "OCL")
 set(PAL_CLIENT_INTERFACE_MAJOR_VERSION     792)
 set(GPUOPEN_CLIENT_INTERFACE_MAJOR_VERSION 42)
 set(GPUOPEN_CLIENT_INTERFACE_MINOR_VERSION 0)
+set(AMD_DK_ROOT $ENV{DK_ROOT})
 
 set(PAL_CLOSED_SOURCE       ON)
 set(PAL_DEVELOPER_BUILD     OFF)