regulator: driver.h: fix regulator_map_* function names

regulator: driver.h: fix regulator_map_* function names

The toolchain produces a warning on this driver when building
the docs:

	./include/linux/regulator/driver.h:284: WARNING: Unknown target name: "regulator_regmap_x_voltage".

While fixing it, we notices that there's no function names
with the above pattern. It seems that some previous patch
renamed it to regulator_map_* instead.

So, change the function name, replacing "x" by "*", with is
a more used way to add a wildcard, and escape those with
``literal`` markup, in order to avoid the toolchain to think
that this is a link to some existing document chapter.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/b9f5687bcf981a88c9d1fd04d759a540fda53a99.1584456635.git.mchehab+huawei@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>