spi: pl022: User more sensible defaults

spi: pl022: User more sensible defaults

When using the device tree, which must be considered normal
these days, in order to get some kind of normal functionality
out of the PL022 users have to actively go into the device
tree and edit the SPI clients like this:

spi {
  compatible = "arm,pl022";
  num-cs = <1>;
  cs-gpios = <&gpio 0 GPIO_ACTIVE_LOW>;

  foo@0 {
    compatible = "foo";
    reg = <0>;
    pl022,interface = <0>;
    pl022,com-mode = <0>;
  };
};

Otherwise the PL022 will come up as a client (slave) and
using polling mode. This is quite unintuitive and many users
will get their device trees wrong.

Alter the defaults such that we come up in host mode
(master) and use interrupt mode.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210328121530.1983081-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>