layout: Implement flashprog_layout_get_region_range()

Similar to the function found in flashrom/master, implement a
libflashprog API to query the range of a layout region.

Change-Id: Idb3b1a4d24a34847102d66ee0e2cb4d93ae99eac
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.sourcearcade.org/c/flashprog/+/72990
diff --git a/include/libflashprog.h b/include/libflashprog.h
index a2ea63c..e1d4d80 100644
--- a/include/libflashprog.h
+++ b/include/libflashprog.h
@@ -83,6 +83,7 @@
 		struct flashprog_flashctx *, const uint8_t *buf, size_t len);
 int flashprog_layout_add_region(struct flashprog_layout *, size_t start, size_t end, const char *name);
 int flashprog_layout_include_region(struct flashprog_layout *, const char *name);
+int flashprog_layout_get_region_range(const struct flashprog_layout *, const char *name, size_t *start, size_t *len);
 void flashprog_layout_release(struct flashprog_layout *);
 void flashprog_layout_set(struct flashprog_flashctx *, const struct flashprog_layout *);