crc16-ccitt: Rename file with CRC-16-CCITT implementation to crc16-ccitt.c

U-Boot CRC-16 implementation uses polynomial x^16 + x^12 + x^5 + 1 which is
not standard CRC-16 algorithm, but it is known as CRC-16-CCITT. Rename file
crc16.c to crc16-ccitt.c to reduce confusion.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/tools/Makefile b/tools/Makefile
index e17271b..9f23396 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -132,7 +132,7 @@
 			$(ROCKCHIP_OBS) \
 			socfpgaimage.o \
 			sunxi_egon.o \
-			lib/crc16.o \
+			lib/crc16-ccitt.o \
 			lib/hash-checksum.o \
 			lib/sha1.o \
 			lib/sha256.o \