defconfig: am437x_sk_evm: enable dma driver model

enable dma driver model for am437x_sk_evm as ti-edma3 supports
driver model

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jagan Teki <jteki@openedev.com>
diff --git a/configs/am437x_sk_evm_defconfig b/configs/am437x_sk_evm_defconfig
index 9eb41f9..3e916db 100644
--- a/configs/am437x_sk_evm_defconfig
+++ b/configs/am437x_sk_evm_defconfig
@@ -23,3 +23,4 @@
 CONFIG_SPI_FLASH_BAR=y
 CONFIG_TIMER=y
 CONFIG_OMAP_TIMER=y
+CONFIG_DMA=y