Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/ssb/sprom.c b/drivers/ssb/sprom.c
index 4f7cc8d..5f34d7a 100644
--- a/drivers/ssb/sprom.c
+++ b/drivers/ssb/sprom.c
@@ -185,7 +185,7 @@
 	/* this routine differs from specs as we do not access SPROM directly
 	   on PCMCIA */
 	if (bus->bustype == SSB_BUSTYPE_PCI &&
-	    bus->chipco.dev &&	/* can be unavailible! */
+	    bus->chipco.dev &&	/* can be unavailable! */
 	    bus->chipco.dev->id.revision >= 31)
 		return bus->chipco.capabilities & SSB_CHIPCO_CAP_SPROM;