Revert "BACKPORT: tracing: Remove unnecessary DEBUG_FS dependency"

This reverts commit 9f66d36f.

This is a preparation change for merging android-5.4.24 into
msm-5.4 branch. The change will be restored into downstream
at later stage, once issues with techpacks are resolved.

Change-Id: If0de301912c986d74e4b89e31d2bee52a0021beb
Signed-off-by: Blagovest Kolenichev <bkolenichev@codeaurora.org>