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/Kconfig b/drivers/mtd/nand/Kconfig
index a92054e..edec457 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -239,7 +239,7 @@
 	help
 	  This enables the NAND flash controller on the BCM UMI block.
 
-	  No board specfic support is done by this driver, each board
+	  No board specific support is done by this driver, each board
 	  must advertise a platform_device for the driver to attach.
 
 config MTD_NAND_BCM_UMI_HWCS