Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/include/linux/usb/ehci_def.h b/include/linux/usb/ehci_def.h
index 6563802..e49dfd4 100644
--- a/include/linux/usb/ehci_def.h
+++ b/include/linux/usb/ehci_def.h
@@ -159,7 +159,7 @@
 #define USBMODE_CM_IDLE	(0<<0)		/* idle state */
 
 /* Moorestown has some non-standard registers, partially due to the fact that
- * its EHCI controller has both TT and LPM support. HOSTPCx are extentions to
+ * its EHCI controller has both TT and LPM support. HOSTPCx are extensions to
  * PORTSCx
  */
 #define HOSTPC0		0x84		/* HOSTPC extension */