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>

include/common.h

@@ -322,9 +322,6 @@ int strcmp_compar(const void *, const void *);
 /* lib/strmhz.c */
 char *	strmhz(char *buf, unsigned long hz);
 
-/* lib/crc32.c */
-#include <u-boot/crc.h>
-
 /*
  * STDIO based functions (can always be used)
  */