dma/rc4030: Fix off-by-one error in specified memory region size

The size is one byte less than it should be:

address-space: rc4030-dma
  0000000000000000-00000000fffffffe (prio 0, i/o): rc4030.dma

rc4030 is used in MIPS Jazz board context.

Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Aleksandar Rikalo <arikalo@wavecomp.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <1561472838-32272-2-git-send-email-aleksandar.markovic@rt-rk.com>

hw/dma/rc4030.c

@@ -23,6 +23,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/units.h"
 #include "hw/hw.h"
 #include "hw/mips/mips.h"
 #include "hw/sysbus.h"
@@ -678,7 +679,7 @@ static void rc4030_realize(DeviceState *dev, Error **errp)
 
     memory_region_init_iommu(&s->dma_mr, sizeof(s->dma_mr),
                              TYPE_RC4030_IOMMU_MEMORY_REGION,
-                             o, "rc4030.dma", UINT32_MAX);
+                             o, "rc4030.dma", 4 * GiB);
     address_space_init(&s->dma_as, MEMORY_REGION(&s->dma_mr), "rc4030-dma");
 }