mips: sibyte: add missing MODULE_DESCRIPTION() macro

Since commit 1fffe7a3 ("script: modpost: emit a warning when the
description is missing"), a module without a MODULE_DESCRIPTION() will
result in a warning with make W=1. The following warning is being
observed when ARCH=mips and CONFIG_SIBYTE_TBPROF=m:

WARNING: modpost: missing MODULE_DESCRIPTION() in arch/mips/sibyte/common/sb_tbprof.o

Add the missing invocation of the MODULE_DESCRIPTION() macro.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/sibyte/common/sb_tbprof.c

@@ -589,4 +589,5 @@ module_exit(sbprof_tb_cleanup);
 
 MODULE_ALIAS_CHARDEV_MAJOR(SBPROF_TB_MAJOR);
 MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
+MODULE_DESCRIPTION("Support for ZBbus profiling");
 MODULE_LICENSE("GPL");