staging: rtl8712: Correct a typo in a comment

Correct a single typo in a comment.
Misspelling found using checkpatch.pl.
Signed-off-by: R Veera Kumar <vkor@vkten.in>
Link: https://lore.kernel.org/r/20200319094358.GA2751@tulip.localSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8712/rtl871x_mp_phy_regdef.h

@@ -30,7 +30,7 @@
 /*--------------------------Define Parameters-------------------------------*/
 
 /*============================================================
- *       8192S Regsiter offset definition
+ *       8192S Register offset definition
  *============================================================
  *
  *