HID: i2c-hid: Disable runtime PM for LG touchscreen

HID: i2c-hid: Disable runtime PM for LG touchscreen

BugLink: https://bugs.launchpad.net/bugs/1805085
LG touchscreen (1fd2:8001) stops working after reboot:
[ 4.859153] i2c_hid i2c-SAPS2101:00: i2c_hid_get_input: incomplete report (64/66)
[ 4.936070] i2c_hid i2c-SAPS2101:00: i2c_hid_get_input: incomplete report (64/66)
[ 9.948224] i2c_hid i2c-SAPS2101:00: failed to reset device.

The device in question stops working after receives SLEEP, ON, SLEEP
commands in a short period. The scenario is like this:
- Once the desktop session closes, it also closed the hid device, so the
device gets runtime suspended and receives a SLEEP command.
- Before calling shutdown callback, it gets runtime resumed and received
an ON command.
- In the shutdown callback, it receives another SLEEP command.

I failed to find a reliable interval between ON/SLEEP commands that can
make it work, so let's simply disable runtime PM for the device.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
(backported from commit 86c31524b27c7e686841dd4a79eda95cfd989f16)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>