mbed: Add implementation of flash_area_get_sectors_fa

Variant of flash_area_get_sectors that takes flash_area object
pointer instead of flash area identifier.

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>

Author: de-nordic

boot/mbed/include/flash_map_backend/flash_map_backend.h

@@ -155,6 +155,8 @@ uint8_t flash_area_erased_val(const struct flash_area * fap);
  */
 int flash_area_get_sectors(int fa_id, uint32_t *count,
   struct flash_sector *sectors);
+int flash_area_get_sectors_fa(const struct flash_area *fa, uint32_t *count,
+  struct flash_sector *sectors);
 
 
 int flash_area_id_from_image_slot(int slot);

boot/mbed/src/flash_map_backend.cpp

@@ -227,6 +227,11 @@ int flash_area_get_sectors(int fa_id, uint32_t* count, struct flash_sector* sect
     return 0;
 }
 
+int flash_area_get_sectors_fa(const struct flash_area *fap, uint32_t* count,
+                              struct flash_sector* sectors) {
+    return flash_area_get_sectors(fap->fa_id, count, sectors);
+}
+
 int flash_area_id_from_image_slot(int slot) {
     return slot;
 }