Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 6e2cdd5..e32b0c2 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -51,7 +51,7 @@
 config GENERIC_CLOCKEVENTS
 	def_bool y
 
-# FIXME: tilegx can implement a more efficent rwsem.
+# FIXME: tilegx can implement a more efficient rwsem.
 config RWSEM_GENERIC_SPINLOCK
 	def_bool y