rtc: rzn1: Use pm_runtime_put_sync()

rtc: rzn1: Use pm_runtime_put_sync()

pm_runtime_put() may trigger the idle check after pm_runtime_disable()
is run as part of devm_pm_runtime_enable()'s cleanup action, leaving
runtime PM active.

Use pm_runtime_put_sync() to ensure the idle check runs synchronously.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://patch.msgid.link/20260821211032.13554-10-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>