power: supply: ab8500: Constify struct kobj_type

This 'struct kobj_type' is not modified. It is only used in
kobject_init_and_add() which takes a 'const struct kobj_type *ktype'
parameter.

Constifying this structure and moving it to a read-only section,
and can increase over all security.

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Link: https://lore.kernel.org/r/20240904011434.2010118-1-lihongbo22@huawei.com


Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>