HAL_ChibiOS: fixed a bug in processing STORAGE_FLASH_PAGE

when we look in hwdef.dat for STORAGE_FLASH_PAGE we need to recurse
into includes, or we may miss it

libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py

@@ -785,6 +785,20 @@ def get_flash_page_offset_kb(sector):
         offset += pages[i]
     return offset
 
+def load_file_with_include(fname):
+    '''load a file as an array of lines, processing any include lines'''
+    lines = open(fname,'r').readlines()
+    ret = []
+    for line in lines:
+        if line.startswith("include"):
+            a = shlex.split(line)
+            if len(a) > 1 and a[0] == "include":
+                fname2 = os.path.relpath(os.path.join(os.path.dirname(fname), a[1]))
+                ret.extend(load_file_with_include(fname2))
+                continue
+        ret.append(line)
+    return ret
+
 def get_storage_flash_page():
     '''get STORAGE_FLASH_PAGE either from this hwdef or from hwdef.dat
        in the same directory if this is a bootloader
@@ -796,7 +810,7 @@ def get_storage_flash_page():
         hwdefdat = args.hwdef[0].replace("-bl", "")
         if os.path.exists(hwdefdat):
             ret = None
-            lines = open(hwdefdat,'r').readlines()
+            lines = load_file_with_include(hwdefdat)
             for line in lines:
                 result = re.match(r'STORAGE_FLASH_PAGE\s*([0-9]+)', line)
                 if result: