x86: Fix various typos in comments

Go over arch/x86/ and fix common typos in comments,
and a typo in an actual function argument name.

No change in functionality intended.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/platform/intel/iosf_mbi.c

@@ -13,7 +13,7 @@
  *
  *
  * The IOSF-SB is a fabric bus available on Atom based SOC's that uses a
- * mailbox interface (MBI) to communicate with mutiple devices. This
+ * mailbox interface (MBI) to communicate with multiple devices. This
  * driver implements access to this interface for those platforms that can
  * enumerate the device using PCI.
  */