arm: ti: Increase malloc size to 16MB for armv7 boards

The current size of 1MB is not enough use to use DFU. Increase it for
ARMv7 boards, all of which should have 32MB or more SDRAM.

With this change it is possible to do 'dfu mmc 0' on a Beaglebone Black.

Signed-off-by: Simon Glass <sjg@chromium.org>

include/configs/ti_armv7_common.h

@@ -127,7 +127,7 @@
  * we are on so we do not need to rely on the command prompt.  We set a
  * console baudrate of 115200 and use the default baud rate table.
  */
-#define CONFIG_SYS_MALLOC_LEN		(1024 << 10)
+#define CONFIG_SYS_MALLOC_LEN		(16 << 20)
 #define CONFIG_SYS_HUSH_PARSER
 #define CONFIG_SYS_PROMPT		"U-Boot# "
 #define CONFIG_SYS_CONSOLE_INFO_QUIET