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/common/image.c b/common/image.c
index f17fa40..992ebba 100644
--- a/common/image.c
+++ b/common/image.c
@@ -9,6 +9,7 @@
 #ifndef USE_HOSTCC
 #include <common.h>
 #include <env.h>
+#include <u-boot/crc.h>
 #include <watchdog.h>
 
 #ifdef CONFIG_SHOW_BOOT_PROGRESS