iommu: rockchip: Free domain on .domain_free

iommu: rockchip: Free domain on .domain_free

BugLink: https://bugs.launchpad.net/bugs/1858429
[ Upstream commit 42bb97b80f2e3bf592e3e99d109b67309aa1b30e ]

IOMMU domain resource life is well-defined, managed
by .domain_alloc and .domain_free.

Therefore, domain-specific resources shouldn't be tied to
the device life, but instead to its domain.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>