msm: kgsl: Use the correct method for exporting trace event functions

Use EXPORT_TRACEPOINT_SYMBOL instead of my lazy "trace" wrappers for
trace_kgsl_regwrite and trace_kgsl_issueibcmds thus saving lots of
code and a shred or two of dignity along the way.

Change-Id: Ic0dedbad4f54a7522edd2f9c3d017ba1e9dba505
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>