cmake: fix partition_table cmake when using md5 checksum

components/partition_table/CMakeLists.txt

@@ -16,7 +16,7 @@ else()
     set(final_partition_target "build_partition_table")
 endif()
 
-if(CONFIG_PARTITION_TABLE_MD5)
+if(NOT CONFIG_PARTITION_TABLE_MD5)
     set(md5_opt --disable-md5sum)
 endif()