intel_th: msu-sink: add missing MODULE_DESCRIPTION()

make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/hwtracing/intel_th/intel_th_msu_sink.o

Add the missing invocation of the MODULE_DESCRIPTION() macro.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240530-md-intel_th_msu_sink-v1-1-ae796336e7b9@quicinc.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/intel_th/msu-sink.c

@@ -116,4 +116,5 @@ static const struct msu_buffer sink_mbuf = {
 
 module_intel_th_msu_buffer(sink_mbuf);
 
+MODULE_DESCRIPTION("example software sink buffer for Intel TH MSU");
 MODULE_LICENSE("GPL v2");