clk: bcm: Add BCM63268 timer clock and reset driver

Add driver for BCM63268 timer clock and reset controller.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Link: https://lore.kernel.org/r/20230322171515.120353-5-noltari@gmail.com
[sboyd@kernel.org: Mark reset ops const, fixup includes]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>