staging: rts5139: Drop print of build time

The kernel already has this information, and individual drivers
shouldn't duplicate that.  This also eliminates the use of __TIME__,
which makes the build non-deterministic.  (And, without __DATE__,
__TIME__ provided little useful information to begin with.)

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>