mfd: ls2kbmc: Fully convert to use managed resources

mfd: ls2kbmc: Fully convert to use managed resources

The mixing of managed and non-managed resources may lead to possible
use-after-free bugs. In this driver the problematic part is the device
functionality that may just have gone behind the functions back, e.g.,
when interrupt is being served. Fix this by switching to managed resources
for PCI.

Fixes: 91a3e1f5453a ("mfd: ls2kbmc: Check for devm_mfd_add_devices() failure")
Fixes: d952bba3fbb5 ("mfd: ls2kbmc: Add Loongson-2K BMC reset function support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Binbin Zhou <zhoubinbin@loongson.cn>
Link: https://patch.msgid.link/20251030113735.3741913-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Lee Jones <lee@kernel.org>