rapids cpm patches now support differences in white space. (rapidsai#515

)

Sometimes projects trim trailing whitespace from diffs, which causes them to not match the source. This allows us to handle those diff files

Authors:
  - Robert Maynard (https://github.com/robertmaynard)

Approvers:
  - Bradley Dice (https://github.com/bdice)

URL: rapidsai#515

rapids-cmake/cpm/patches/command_template.cmake.in

@@ -37,7 +37,7 @@ function(rapids_cpm_run_git_patch file issue)
   set(result 1)
   if(ext STREQUAL "diff")
     execute_process(
-      COMMAND ${git_command} apply ${file}
+      COMMAND ${git_command} apply --whitespace=fix ${file}
       RESULT_VARIABLE result
       ERROR_VARIABLE repo_error_info
     )