env: Move env_set_hex() to env.h

Move env_set_hex() over to the new header file along with env_set_addr()
which uses it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/fastboot/fb_command.c b/drivers/fastboot/fb_command.c
index 200f991..4864344 100644
--- a/drivers/fastboot/fb_command.c
+++ b/drivers/fastboot/fb_command.c
@@ -4,6 +4,7 @@
  */
 
 #include <common.h>
+#include <env.h>
 #include <fastboot.h>
 #include <fastboot-internal.h>
 #include <fb_mmc.h>
diff --git a/drivers/net/fm/fm.c b/drivers/net/fm/fm.c
index 0a43dfe..ce0f167 100644
--- a/drivers/net/fm/fm.c
+++ b/drivers/net/fm/fm.c
@@ -4,6 +4,7 @@
  *	Dave Liu <daveliu@freescale.com>
  */
 #include <common.h>
+#include <env.h>
 #include <malloc.h>
 #include <asm/io.h>
 #include <linux/errno.h>
diff --git a/drivers/usb/gadget/f_sdp.c b/drivers/usb/gadget/f_sdp.c
index fab7ce6..bcd1c5d 100644
--- a/drivers/usb/gadget/f_sdp.c
+++ b/drivers/usb/gadget/f_sdp.c
@@ -19,6 +19,7 @@
 #include <errno.h>
 #include <common.h>
 #include <console.h>
+#include <env.h>
 #include <malloc.h>
 
 #include <linux/usb/ch9.h>