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/env/sf.c b/env/sf.c
index 16dba11..5ef4055 100644
--- a/env/sf.c
+++ b/env/sf.c
@@ -18,6 +18,7 @@
 #include <search.h>
 #include <errno.h>
 #include <dm/device-internal.h>
+#include <u-boot/crc.h>
 
 #ifndef CONFIG_SPL_BUILD
 #define CMD_SAVEENV