ptp_qoriq: fix memory leak in probe()

Smatch complains that:
drivers/ptp/ptp_qoriq.c ptp_qoriq_probe()
warn: 'base' from ioremap() not released.

Fix this by revising the parameter from 'ptp_qoriq->base' to 'base'.
This is only a bug if ptp_qoriq_init() returns on the
first -ENODEV error path.
For other error paths ptp_qoriq->base and base are the same.
And this change makes the code more readable.

Fixes: 7f4399ba

 ("ptp_qoriq: fix NULL access if ptp dt node missing")
Signed-off-by: SongJingyi <u201912584@hust.edu.cn>
Reviewed-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Link: https://lore.kernel.org/r/20230324031406.1895159-1-u201912584@hust.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>