ARM: dts: vexpress: align LED node names with dtschema

ARM: dts: vexpress: align LED node names with dtschema

The node names should be generic and DT schema expects certain pattern.

  vexpress-v2p-ca9.dtb: leds: 'user1', 'user2', 'user3', 'user4', 'user5', 'user6', 'user7', 'user8' do not match any of the regexes: '(^led-[0-9a-f]$|led)', 'pinctrl-[0-9]+'

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221125144112.476817-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>