Fix FDT_DTS_FILE parsing to properly retrieve its value. This unbreaks the 'builddtb' target.
Fix FDT_DTS_FILE parsing to properly retrieve its value. This unbreaks the
'builddtb' target.

Make the processing more robust against non-existent kernel config files
(pointed out by imp@).

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase