siemens-am33x-common: Drop CONFIG_DMA_COHERENT*

These values are not used in the code, remove them.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/include/configs/siemens-am33x-common.h b/include/configs/siemens-am33x-common.h
index bfadf4a..08c4d52 100644
--- a/include/configs/siemens-am33x-common.h
+++ b/include/configs/siemens-am33x-common.h
@@ -15,9 +15,6 @@
 
 #include <asm/arch/omap.h>
 
-#define CONFIG_DMA_COHERENT
-#define CONFIG_DMA_COHERENT_SIZE	(1 << 20)
-
 /* commands to include */
 
 #ifndef CONFIG_SPL_BUILD