MIPS: Au1550: Fix OHCI memory map size

    
USB OpenHCI host controller on Au1550 only decodes memory addresses from
0x14020000 to 0x1407FFFF according to the databook, which gives 0x60000
(on the prior Au1x00 chips the map size was 1MB).
    
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Acked-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>