da850: indicate cache usage disable in config file

there are cache coherency issues when using the DAVINCI Ethernet driver,
hence caches cant be used for da850 u-boot. As per new cache management
framework,if the caches are not used in u-boot, it needs to be explicitly
indicated through macros in config file. CACHE disable is  indicated by
the following macro definitions in config file,

1. CONFIG_SYS_ICACHE_OFF
2. CONFIG_SYS_DCACHE_OFF
3. CONFIG_SYS_L2CACHE_OFF

Signed-off-by: Nagabhushana Netagunte <nagabhushana.netagunte@ti.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

include/configs/da850evm.h

@@ -42,6 +42,9 @@
 #define CONFIG_SYS_HZ			1000
 #define CONFIG_SKIP_LOWLEVEL_INIT
 #define CONFIG_SYS_TEXT_BASE		0xc1080000
+#define CONFIG_SYS_ICACHE_OFF
+#define CONFIG_SYS_DCACHE_OFF
+#define CONFIG_SYS_L2CACHE_OFF
 
 /*
  * Memory Info