power: remove pda_power supply driver

This driver was used for a couple of Intel PXA and Samsung S3C24xx
based PDAs, but all of those are now removed from the kernel, so
the driver itself is no longer useful.

Cc: Anton Vorontsov <cbou@mail.ru>
Cc: linux-pm@vger.kernel.org
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

dt-bindings: power: update battery.yaml reference

Changesets: 70c23e62d20c ("dt-bindings: power: supply: Fix remaining battery.txt links")
and: 471dec8023d1 ("dt-bindings: power: Convert battery.txt to battery.yaml")
renamed: Documentation/devicetree/bindings/power/supply/battery.txt
to: Documentation/devicetree/bindings/power/supply/battery.yaml.

Update its cross-reference accordingly.

Fixes: 70c23e62d20c ("dt-bindings: power: supply: Fix remaining battery.txt links")
Fixes: 471dec8023d1 ("dt-bindings: power: Convert battery.txt to battery.yaml")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

docs: power: convert docs to ReST and rename to *.rst

Convert the PM documents to ReST, in order to allow them to
build with Sphinx.

The conversion is actually:
- add blank lines and indentation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>