ARM: omap2+: Downgrade u-boot version warnings to debug statements

We should be able to see real issues with dmesg -l err,warn. The u-boot
revision warning should be a debug statement rather than a warning.

Cc: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Cc: Carl Philipp Klemm <philipp@uvos.xyz>
Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/pm44xx.c

@@ -99,7 +99,7 @@ static int omap4_pm_suspend(void)
 		 * possible causes.
 		 * http://www.spinics.net/lists/arm-kernel/msg218641.html
 		 */
-		pr_warn("A possible cause could be an old bootloader - try u-boot >= v2012.07\n");
+		pr_debug("A possible cause could be an old bootloader - try u-boot >= v2012.07\n");
 	} else {
 		pr_info("Successfully put all powerdomains to target state\n");
 	}
@@ -257,7 +257,7 @@ int __init omap4_pm_init(void)
 	 * http://www.spinics.net/lists/arm-kernel/msg218641.html
 	 */
 	if (cpu_is_omap44xx())
-		pr_warn("OMAP4 PM: u-boot >= v2012.07 is required for full PM support\n");
+		pr_debug("OMAP4 PM: u-boot >= v2012.07 is required for full PM support\n");
 
 	ret = pwrdm_for_each(pwrdms_setup, NULL);
 	if (ret) {