riscv: htif: increase the priority of the htif subregion

riscv: htif: increase the priority of the htif subregion

The htif device is supposed to be mapped over an other subregion. So increase
its priority to one to avoid any conflict.

Here is the output of info mtree:

Before:
(qemu) info mtree
 address-space: memory
   0000000000000000-ffffffffffffffff (prio 0, i/o): system
     0000000000000000-000000000000000f (prio 0, i/o): riscv.htif.uart
     0000000000000000-0000000000011fff (prio 0, ram): riscv.spike.bootrom
     0000000002000000-000000000200ffff (prio 0, i/o): riscv.sifive.clint
     0000000080000000-0000000087ffffff (prio 0, ram): riscv.spike.ram

 address-space: I/O
   0000000000000000-000000000000ffff (prio 0, i/o): io

 address-space: cpu-memory-0
   0000000000000000-ffffffffffffffff (prio 0, i/o): system
     0000000000000000-000000000000000f (prio 0, i/o): riscv.htif.uart
     0000000000000000-0000000000011fff (prio 0, ram): riscv.spike.bootrom
     0000000002000000-000000000200ffff (prio 0, i/o): riscv.sifive.clint
     0000000080000000-0000000087ffffff (prio 0, ram): riscv.spike.ram

After:
 (qemu) info mtree
 address-space: memory
   0000000000000000-ffffffffffffffff (prio 0, i/o): system
     0000000000000000-000000000000000f (prio 1, i/o): riscv.htif.uart
     0000000000000000-0000000000011fff (prio 0, ram): riscv.spike.bootrom
     0000000002000000-000000000200ffff (prio 0, i/o): riscv.sifive.clint
     0000000080000000-0000000087ffffff (prio 0, ram): riscv.spike.ram

 address-space: I/O
   0000000000000000-000000000000ffff (prio 0, i/o): io

 address-space: cpu-memory-0
   0000000000000000-ffffffffffffffff (prio 0, i/o): system
     0000000000000000-000000000000000f (prio 1, i/o): riscv.htif.uart
     0000000000000000-0000000000011fff (prio 0, ram): riscv.spike.bootrom
     0000000002000000-000000000200ffff (prio 0, i/o): riscv.sifive.clint
     0000000080000000-0000000087ffffff (prio 0, ram): riscv.spike.ram

Reviewed-by: Michael Clark <mjc@sifive.com>
Signed-off-by: KONRAD Frederic <frederic.konrad@adacore.com>
Signed-off-by: Michael Clark <mjc@sifive.com>
Message-Id: <1525360636-18229-3-git-send-email-frederic.konrad@adacore.com>
(cherry picked from commit 6fad7d1893f6ea926063067af957009bc320406f)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>