ARM: shmobile: ape6evm dts: Fix polarity of LEDs

While the LEDs on r8a73a4/ape6evm are tied to VSUPPLY, they're driven by
an N-channel MOSFET. Hence the GPIO signal should be active high.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>