[POWERPC] Spelling fixes: arch/ppc/

Spelling fixes in arch/ppc/.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/ppc/syslib/ppc405_pci.c b/arch/ppc/syslib/ppc405_pci.c
index d6d838b..9e90356 100644
--- a/arch/ppc/syslib/ppc405_pci.c
+++ b/arch/ppc/syslib/ppc405_pci.c
@@ -137,7 +137,7 @@
 	hose_a->pci_mem_offset = 0;
 
 	/* Setup bridge memory/IO ranges & resources
-	 * TODO: Handle firmwares setting up a legacy ISA mem base
+	 * TODO: Handle firmware setting up a legacy ISA mem base
 	 */
 	hose_a->io_space.start = PPC405_PCI_LOWER_IO;
 	hose_a->io_space.end = PPC405_PCI_UPPER_IO;