net: dsa: qca8k: add LEDs basic support

Add LEDs basic support for qca8k Switch Family by adding basic
brightness_set() support.

Since these LEDs refelect port status, the default label is set to
":port". DT binding should describe the color and function of the
LEDs using standard LEDs api.
Each LED always have the device name as prefix. The device name is
composed from the mii bus id and the PHY addr resulting in example
names like:
- qca8k-0.0:00:amber:lan
- qca8k-0.0:00:white:lan
- qca8k-0.0:01:amber:lan
- qca8k-0.0:01:white:lan

These LEDs supports only blocking variant of the brightness_set()
function since they can sleep during access of the switch leds to set
the brightness.

While at it add to the qca8k header file each mode defined by the Switch
Documentation for future use.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: qca8k: move mib struct to common code

The same MIB struct is used by drivers based on qca8k family switch. Move
it to common code to make it accessible also by other drivers.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dsa: qca8k: move driver to qca dir

Move qca8k driver to qca dir in preparation for code split and
introduction of ipq4019 switch based on qca8k.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: add support for Atheros AR9331 built-in switch

Provide basic support for Atheros AR9331 built-in switch. So far it
works as port multiplexer without any hardware offloading support.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>