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

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>