ads5121: enable instruction cache

Enabling the instruction cache significantly accelerates U-Boot
operations like CRC checking, image uncompression, etc.

Kudos to Andrea Scian for pointing out.
Signed-off-by: NWolfgang Denk <wd@denx.de>

include/configs/ads5121.h

@@ -411,7 +411,7 @@
 #endif
 
 #define CONFIG_SYS_HID0_INIT	0x000000000
-#define CONFIG_SYS_HID0_FINAL	HID0_ENABLE_MACHINE_CHECK
+#define CONFIG_SYS_HID0_FINAL	(HID0_ENABLE_MACHINE_CHECK | HID0_ICE)
 #define CONFIG_SYS_HID2	HID2_HBE
 
 #define CONFIG_HIGH_BATS	1	/* High BATs supported */