Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/arch/cris/include/asm/pgtable.h b/arch/cris/include/asm/pgtable.h
index 9eaae21..7df4301 100644
--- a/arch/cris/include/asm/pgtable.h
+++ b/arch/cris/include/asm/pgtable.h
@@ -97,7 +97,7 @@
 #define pte_clear(mm,addr,xp)	do { pte_val(*(xp)) = 0; } while (0)
 
 #define pmd_none(x)     (!pmd_val(x))
-/* by removing the _PAGE_KERNEL bit from the comparision, the same pmd_bad
+/* by removing the _PAGE_KERNEL bit from the comparison, the same pmd_bad
  * works for both _PAGE_TABLE and _KERNPG_TABLE pmd entries.
  */
 #define	pmd_bad(x)	((pmd_val(x) & (~PAGE_MASK & ~_PAGE_KERNEL)) != _PAGE_TABLE)