crc32: Use the crc.h header for crc functions

Drop inclusion of crc.h in common.h and use the correct header directly
instead.

With this we can drop the conflicting definition in fw_env.h and rely on
the crc.h header, which is already included.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/board/gardena/smart-gateway-mt7688/board.c b/board/gardena/smart-gateway-mt7688/board.c
index e9ffd42..fea823b 100644
--- a/board/gardena/smart-gateway-mt7688/board.c
+++ b/board/gardena/smart-gateway-mt7688/board.c
@@ -10,6 +10,7 @@
 #include <net.h>
 #include <spi.h>
 #include <spi_flash.h>
+#include <u-boot/crc.h>
 #include <uuid.h>
 #include <linux/ctype.h>
 #include <linux/io.h>