x86: fix mtrr missing kernel-doc

Fix missing kernel-doc notation in mtrr/main.c:

Warning(arch/x86/kernel/cpu/mtrr/main.c:152): No description found for parameter 'info'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/kernel/cpu/mtrr/main.c

@@ -145,6 +145,7 @@ struct set_mtrr_data {
 
 /**
  * ipi_handler - Synchronisation handler. Executed by "other" CPUs.
+ * @info: pointer to mtrr configuration data
  *
  * Returns nothing.
  */