clocksource/drivers/nxp-stm: Prevent driver unbind

clocksource/drivers/nxp-stm: Prevent driver unbind

Clockevents cannot be deregistered so suppress the bind attributes to
prevent the driver from being unbound and releasing the underlying
resources after registration.

Even if the driver can currently only be built-in, also switch to
builtin_platform_driver() to prevent it from being unloaded should
modular builds ever be enabled.

Fixes: cec32ac75827 ("clocksource/drivers/nxp-timer: Add the System Timer Module for the s32gx platforms")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://patch.msgid.link/20251111153226.579-4-johan@kernel.org