serial: qcom-geni: Fix blocked task

In the Linux kernel, the following vulnerability has been resolved:

serial: qcom-geni: Fix blocked task

Revert commit 1afa70632c39 ("serial: qcom-geni: Enable PM runtime for
serial driver") and its dependent commit 86fa39dd6fb7 ("serial:
qcom-geni: Enable Serial on SA8255p Qualcomm platforms") because the
first one causes regression - hang task on Qualcomm RB1 board (QRB2210)
and unable to use serial at all during normal boot:

INFO: task kworker/u16:0:12 blocked for more than 42 seconds.
Not tainted 6.17.0-rc1-00004-g53e760d89498 #9
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u16:0 state:D stack:0 pid:12 tgid:12 ppid:2 task_flags:0x4208060 flags:0x00000010
Workqueue: async async_run_entry_fn
Call trace:
__switch_to+0xe8/0x1a0 (T)
__schedule+0x290/0x7c0
schedule+0x34/0x118
rpm_resume+0x14c/0x66c
rpm_resume+0x2a4/0x66c
rpm_resume+0x2a4/0x66c
rpm_resume+0x2a4/0x66c
__pm_runtime_resume+0x50/0x9c
__driver_probe_device+0x58/0x120
driver_probe_device+0x3c/0x154
__driver_attach_async_helper+0x4c/0xc0
async_run_entry_fn+0x34/0xe0
process_one_work+0x148/0x290
worker_thread+0x2c4/0x3e0
kthread+0x118/0x1c0
ret_from_fork+0x10/0x20

The issue was reported on 12th of August and was ignored by author of
commits introducing issue for two weeks. Only after complaining author
produced a fix which did not work, so if original commits cannot be
reliably fixed for 5 weeks, they obviously are buggy and need to be
dropped.