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>

lib/gunzip.c

@@ -12,6 +12,7 @@
 #include <image.h>
 #include <malloc.h>
 #include <memalign.h>
+#include <u-boot/crc.h>
 #include <watchdog.h>
 #include <u-boot/zlib.h>