dt-bindings: pinctrl: sunxi: Allow pinmux sub-pattern with leading numbers

dt-bindings: pinctrl: sunxi: Allow pinmux sub-pattern with leading numbers

The pattern for pinmux node names is typically the peripheral name and
instance number, followed by pingroup name if there are multiple options.

Normally the instance number is directly appended to the peripheral
name, like "mmc0" or "i2c2". But if the peripheral name ends with a
number, then it becomes confusing.

On the A20, the PS2 interface controller has two instances. This
produces pinmux node names like "ps2-0-pins". Make the sub-pattern
"[0-9]-" valid to fit this pattern. Avoid having to confusing "ps20-pins"
name.

Signed-off-by: Chen-Yu Tsai <wens@kernel.org>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Linus Walleij <linusw@kernel.org>