Fix Python Bindings after changes to cs_detail

capstone-engine#2034 changed the `regs_read` array size and added a new `writeback`
element to the cs_detail struct.

Those changes weren't reflected in the Python bindings causing details
to be missing.

bindings/python/capstone/__init__.py

@@ -407,12 +407,13 @@ class _cs_arch(ctypes.Union):
 
 class _cs_detail(ctypes.Structure):
     _fields_ = (
-        ('regs_read', ctypes.c_uint16 * 16),
+        ('regs_read', ctypes.c_uint16 * 20),
         ('regs_read_count', ctypes.c_ubyte),
         ('regs_write', ctypes.c_uint16 * 20),
         ('regs_write_count', ctypes.c_ubyte),
         ('groups', ctypes.c_ubyte * 8),
         ('groups_count', ctypes.c_ubyte),
+        ('writeback', ctypes.c_bool),
         ('arch', _cs_arch),
     )