[compiler-rt][CMake] Do not explicitly set CMP0114 to old (#90386)
This was added in def0823f1d2db78c4a18b15084407734a45e96c5 to fix a bot
failure, specifically for the standalone build. This does not seem to be
an issue anymore, and setting the policy explicitly to OLD causes
warnings with newer CMake versions.
This patch removes setting the policy to OLD to get rid of the warning.