ARM: dts: omap: echo: use preferred enable-gpios for LP5523 LED

ARM: dts: omap: echo: use preferred enable-gpios for LP5523 LED

The preferred name suffix for properties with single and multiple GPIOs
is "gpios".  Linux GPIO core code supports both.  Bindings are going to
expect the "gpios" one:

  omap3-echo.dtb: lp5523A@32: 'enable-gpio' does not match any of the regexes: '^led@[0-8]$', '^multi-led@[0-8]$', 'pinctrl-[0-9]+'

Acked-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20221127203034.54092-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>