iommu/rockchip: Fix unwind goto issue

Smatch complains that
drivers/iommu/rockchip-iommu.c:1306 rk_iommu_probe() warn: missing unwind goto?

The rk_iommu_probe function, after obtaining the irq value through
platform_get_irq, directly returns an error if the returned value
is negative, without releasing any resources.

Fix this by adding a new error handling label "err_pm_disable" and
use a goto statement to redirect to the error handling process. In
order to preserve the original semantics, set err to the value of irq.

Fixes: 1aa55ca9

 ("iommu/rockchip: Move irq request past pm_runtime_enable")
Signed-off-by: Chao Wang <D202280639@hust.edu.cn>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20230417030421.2777-1-D202280639@hust.edu.cn
Signed-off-by: Joerg Roedel <jroedel@suse.de>