Kconfig: Rename CONFIG_SPL_DMA_SUPPORT to CONFIG_SPL_DMA

Rename CONFIG_SPL_DMA_SUPPORT to CONFIG_SPL_DMA. This allows to use
macros such as CONFIG_IS_ENABLED() that allow conditional compilation of
code for SPL and U-Boot.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/imx6ul_geam_nand_defconfig b/configs/imx6ul_geam_nand_defconfig
index a344ad1..bb3fc6c 100644
--- a/configs/imx6ul_geam_nand_defconfig
+++ b/configs/imx6ul_geam_nand_defconfig
@@ -20,7 +20,7 @@
 CONFIG_BOOTDELAY=3
 CONFIG_SUPPORT_RAW_INITRD=y
 CONFIG_BOUNCE_BUFFER=y
-CONFIG_SPL_DMA_SUPPORT=y
+CONFIG_SPL_DMA=y
 CONFIG_SPL_WATCHDOG_SUPPORT=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="geam6ul> "