Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 9a87823..885be09 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -249,7 +249,7 @@
  * cache totally.  This means that the cache becomes inconsistent, and,
  * since we use normal loads/stores as well, this is really bad.
  * Typically, this causes oopsen in filp_close, but could have other,
- * more disasterous effects.  There are two work-arounds:
+ * more disastrous effects.  There are two work-arounds:
  *  1. Disable interrupts and emulate the atomic swap
  *  2. Clean the cache, perform atomic swap, flush the cache
  *