Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index a1e8b300..af46428 100644
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -945,7 +945,7 @@
 		rd2 = NULL;
 		/* Per chip or per device ? */
 		chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
-		/* Mirrored table avilable ? */
+		/* Mirrored table available ? */
 		if (md) {
 			if (td->pages[i] == -1 && md->pages[i] == -1) {
 				writeops = 0x03;