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/imx6q_logic_defconfig b/configs/imx6q_logic_defconfig
index 81464ad..a0df286 100644
--- a/configs/imx6q_logic_defconfig
+++ b/configs/imx6q_logic_defconfig
@@ -24,7 +24,7 @@
 CONFIG_SPL_RAW_IMAGE_SUPPORT=y
 CONFIG_SPL_SEPARATE_BSS=y
 # CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR is not set
-CONFIG_SPL_DMA_SUPPORT=y
+CONFIG_SPL_DMA=y
 CONFIG_SPL_I2C_SUPPORT=y
 CONFIG_SPL_NAND_SUPPORT=y
 CONFIG_SPL_OS_BOOT=y