fastboot: support for overriding format fs-type and size

This changes allows overriding the fs-type and size that
are normally returned by the booloader.

This is in preparation for supporting other FSes.

Change-Id: I8d141a0d4d14df9fe84d3b131484e9696fcd8870
Signed-off-by: JP Abgrall <jpa@google.com>
diff --git a/fastboot/fastboot.h b/fastboot/fastboot.h
index c510a36..fc5d4f4 100644
--- a/fastboot/fastboot.h
+++ b/fastboot/fastboot.h
@@ -45,7 +45,7 @@
 
 /* engine.c - high level command queue engine */
 int fb_getvar(struct usb_handle *usb, char *response, const char *fmt, ...);
-int fb_format_supported(usb_handle *usb, const char *partition);
+int fb_format_supported(usb_handle *usb, const char *partition, const char *type_override);
 void fb_queue_flash(const char *ptn, void *data, unsigned sz);
 void fb_queue_flash_sparse(const char *ptn, struct sparse_file *s, unsigned sz);
 void fb_queue_erase(const char *ptn);