xea: spl: Disable pull UP for GPIO0_2{35}

On the imx287 pin GPMI_WRN (GPIO0_25) no PullUP is available that can be
enabled.

To get the same behavior for both boot select pins (i.e. GPIO0_2{35})
disable pull UPs on both.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
diff --git a/board/liebherr/xea/spl_xea.c b/board/liebherr/xea/spl_xea.c
index d88b75b..192f68f 100644
--- a/board/liebherr/xea/spl_xea.c
+++ b/board/liebherr/xea/spl_xea.c
@@ -20,7 +20,7 @@
 #include <asm/arch/sys_proto.h>
 
 #define	MUX_CONFIG_LCD	(MXS_PAD_3V3 | MXS_PAD_4MA | MXS_PAD_NOPULL)
-#define	MUX_CONFIG_BOOT	(MXS_PAD_3V3 | MXS_PAD_PULLUP)
+#define	MUX_CONFIG_BOOT	(MXS_PAD_3V3)
 #define	MUX_CONFIG_TSC	(MXS_PAD_3V3 | MXS_PAD_8MA | MXS_PAD_PULLUP)
 #define	MUX_CONFIG_SSP0	(MXS_PAD_3V3 | MXS_PAD_12MA | MXS_PAD_PULLUP)
 #define	MUX_CONFIG_SSP2	(MXS_PAD_3V3 | MXS_PAD_4MA | MXS_PAD_PULLUP)