mx27ads: move PBC mapping out of vmalloc space

Before this patch I got the following line in my dmesg:

	[    0.000000] BUG: mapping for 0xd4000000 at 0xeb000000 overlaps vmalloc space

VMALLOC_END is 0xf4000000 and there are the following other mappings
defined for mx27ads:

	(0xa0500000,+0x00001000) maps to 0xffff0000
	(0x10000000,+0x00100000) maps to 0xf4000000
	(0x80000000,+0x00100000) maps to 0xf4100000
	(0xd8000000,+0x00100000) maps to 0xf4200000

So map PBC to 0xf4300000.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>