lib: merge CRC16-CCITT into u-boot/crc.h

This merges the CRC16-CCITT headers into u-boot/crc.h to prepare for
rolling CRC16 into the hash infrastructure.  Given that CRC8, CRC32
and CRC32-C already have their prototypes in a single header file, it
seems a good idea to also include CRC16-CCITT in the same.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/board/8dtech/eco5pk/eco5pk.c b/board/8dtech/eco5pk/eco5pk.c
index e05928f..dcbd483 100644
--- a/board/8dtech/eco5pk/eco5pk.c
+++ b/board/8dtech/eco5pk/eco5pk.c
@@ -16,7 +16,7 @@
 #include <asm/arch/emac_defs.h>
 #include <asm/gpio.h>
 #include <i2c.h>
-#include <crc.h>
+#include <u-boot/crc.h>
 #include <asm/mach-types.h>
 #include "eco5pk.h"