src/soc: Fix various typos

These typos were found through manual review and grep.

Change-Id: I6693a9e3b51256b91342881a7116587f68ee96e6
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/23706
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/soc/amd/stoneyridge/southbridge.c

@@ -75,7 +75,7 @@ void SetFchMidParams(FCH_INTERFACE *params)
 
 /*
  * Table of APIC register index and associated IRQ name. Using IDX_XXX_NAME
- * provides a visible association with the index, therefor helping
+ * provides a visible association with the index, therefore helping
  * maintainability of table. If a new index/name is defined in
  * amd_pci_int_defs.h, just add the pair at the end of this table.
  * Order is not important.