This has not worked with any kernel I've tried, from 4.15 to 4.18 to the upstream 4.19 you linked to.
Here's some relevant dmesg output from the v4.19:
[ 1.390898] i2c_hid i2c-ELAN469D:00: i2c-ELAN469D:00 supply vdd not found, using dummy regulator
[ 1.390914] i2c_hid i2c-ELAN469D:00: Linked as a consumer to regulator.0
[ 1.390915] i2c_hid i2c-ELAN469D:00: i2c-ELAN469D:00 supply vddl not found, using dummy regulator
[ 2.420872] i2c_designware AMDI0010:01: controller timed out
This has not worked with any kernel I've tried, from 4.15 to 4.18 to the upstream 4.19 you linked to.
Here's some relevant dmesg output from the v4.19:
[ 1.390898] i2c_hid i2c-ELAN469D:00: i2c-ELAN469D:00 supply vdd not found, using dummy regulator
[ 1.390914] i2c_hid i2c-ELAN469D:00: Linked as a consumer to regulator.0
[ 1.390915] i2c_hid i2c-ELAN469D:00: i2c-ELAN469D:00 supply vddl not found, using dummy regulator
[ 2.420872] i2c_designware AMDI0010:01: controller timed out