arm: omap2: use string choices helper

We can use string choices helper, let's use it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Reviewed-by: Andreas Kemnade <andreas@kemnade.info>
Link: https://lore.kernel.org/r/87ikjq5kqm.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

Author: morimoto

arch/arm/mach-omap2/board-n8x0.c

@@ -167,7 +167,7 @@ static int n8x0_mmc_set_power_menelaus(struct device *dev, int slot,
 
 #ifdef CONFIG_MMC_DEBUG
 	dev_dbg(dev, "Set slot %d power: %s (vdd %d)\n", slot + 1,
-		power_on ? "on" : "off", vdd);
+		str_on_off(power_on), vdd);
 #endif
 	if (slot == 0) {
 		if (!power_on)