regulator: core.c: Replace references to non-existent function

regulator: core.c: Replace references to non-existent function

The function regulator_set_device_supply() is referenced a few times in
comments in regulator/core.c; however this function was removed a long
time ago by commit a5766f11cfd3 ("regulator: core - Rework machine API to
remove string based functions."). Update those references to point to
set_consumer_device_supply(), which replaced the old function.

Signed-off-by: Daniel Scally <djrscally@gmail.com>
Link: https://lore.kernel.org/r/20210103165541.784360-1-djrscally@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>