dt-bindings: mfd: allwinner,sun6i-a31-prcm: Use hyphens in node names

dt-bindings: mfd: allwinner,sun6i-a31-prcm: Use hyphens in node names

Underscores should not be used in node names (dtc with W=2 warns about
them), so replace them with hyphens.  This should have no impact on
known users: Linux MFD driver does not care about children node names.
DTS was already adjusted in commit 0f47ef3ff1bd ("arm: dts: allwinner: drop
underscore in node names"), so without this change, we observe
dtbs_check warnings:

  sun6i-a31s-colorfly-e708-q1.dtb: prcm@1f01400: 'ahb0-clk', 'apb0-clk', 'apb0-gates-clk', 'apb0-rst', 'ar100-clk', 'ir-clk' do not match any of the regexes: '^.*_(clk|rst)$', 'pinctrl-[0-9]+'

Reported-by: Rob Herring <robh@kernel.org>
Closes: https://lore.kernel.org/all/CAL_JsqJfT-jui5P56CO4Fr37kr5iNN8dpxt8ecKeFmdVGnRYbA@mail.gmail.com/
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20240424045521.31857-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>