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/common/spl/Kconfig b/common/spl/Kconfig
index 61488da..c43eed2 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -488,7 +488,7 @@
 	  this option to build system-specific drivers for hash acceleration
 	  as part of an SPL build.
 
-config SPL_DMA_SUPPORT
+config SPL_DMA
 	bool "Support DMA drivers"
 	help
 	  Enable DMA (direct-memory-access) drivers in SPL. These drivers