treewide: Fix typo in Kconfig

Correct spelling typo in Kconfig.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index daa4da2..6ada8b3 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -300,7 +300,7 @@
 	depends on (ARCH_MMP || ARCH_PXA)
 	select DMA_ENGINE
 	help
-	  Support the MMP PDMA engine for PXA and MMP platfrom.
+	  Support the MMP PDMA engine for PXA and MMP platform.
 
 config DMA_JZ4740
 	tristate "JZ4740 DMA support"