Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

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

drivers/ata/ata_piix.c

@@ -38,16 +38,16 @@
  *  Hardware documentation available at http://developer.intel.com/
  *
  * Documentation
- *	Publically available from Intel web site. Errata documentation
- * is also publically available. As an aide to anyone hacking on this
+ *	Publicly available from Intel web site. Errata documentation
+ * is also publicly available. As an aide to anyone hacking on this
  * driver the list of errata that are relevant is below, going back to
  * PIIX4. Older device documentation is now a bit tricky to find.
  *
  * The chipsets all follow very much the same design. The original Triton
- * series chipsets do _not_ support independant device timings, but this
+ * series chipsets do _not_ support independent device timings, but this
  * is fixed in Triton II. With the odd mobile exception the chips then
  * change little except in gaining more modes until SATA arrives. This
- * driver supports only the chips with independant timing (that is those
+ * driver supports only the chips with independent timing (that is those
  * with SITRE and the 0x44 timing register). See pata_oldpiix and pata_mpiix
  * for the early chip drivers.
  *
@@ -122,7 +122,7 @@ enum {
 	P2			= 2,  /* port 2 */
 	P3			= 3,  /* port 3 */
 	IDE			= -1, /* IDE */
-	NA			= -2, /* not avaliable */
+	NA			= -2, /* not available */
 	RV			= -3, /* reserved */
 
 	PIIX_AHCI_DEVICE	= 6,