Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

arch/arm/plat-omap/devices.c

@@ -280,7 +280,7 @@ EXPORT_SYMBOL(omap_dsp_get_mempool_base);
  * Claiming GPIOs, and setting their direction and initial values, is the
  * responsibility of the device drivers.  So is responding to probe().
  *
- * Board-specific knowlege like creating devices or pin setup is to be
+ * Board-specific knowledge like creating devices or pin setup is to be
  * kept out of drivers as much as possible.  In particular, pin setup
  * may be handled by the boot loader, and drivers should expect it will
  * normally have been done by the time they're probed.