ARM: rmobile: alt: Increase USB power-good delay

Increase the USB power good delay on Alt, this is required with
certain USB sticks, otherwise they might not be detected.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/include/configs/alt.h b/include/configs/alt.h
index 3f7f379..3a515ee 100644
--- a/include/configs/alt.h
+++ b/include/configs/alt.h
@@ -39,7 +39,8 @@
 #define CONFIG_SYS_CLK_FREQ	RMOBILE_XTAL_CLK
 
 #define CONFIG_EXTRA_ENV_SETTINGS	\
-	"bootm_size=0x10000000\0"
+	"bootm_size=0x10000000\0"	\
+	"usb_pgood_delay=2000\0"
 
 /* SPL support */
 #define CONFIG_SPL_TEXT_BASE		0xe6300000