Merge remote-tracking branch 'remotes/alistair/tags/pull-riscv-to-apply-20200713...

This is a colection of bug fixes and small imrprovements for RISC-V.

This includes some vector extensions fixes, a PMP bug fix, OpenTitan
UART bug fix and support for OpenSBI dynamic firmware.

# gpg: Signature made Tue 14 Jul 2020 01:29:44 BST
# gpg:                using RSA key F6C4AC46D4934868D3B8CE8F21E10D29DF977054
# gpg: Good signature from "Alistair Francis <alistair@alistair23.me>" [full]
# Primary key fingerprint: F6C4 AC46 D493 4868 D3B8  CE8F 21E1 0D29 DF97 7054

* remotes/alistair/tags/pull-riscv-to-apply-20200713:
  target/riscv: Fix pmp NA4 implementation
  tcg/riscv: Remove superfluous breaks
  hw/char: Convert the Ibex UART to use the registerfields API
  hw/char: Convert the Ibex UART to use the qdev Clock model
  target/riscv: fix vill bit index in vtype register
  target/riscv: fix return value of do_opivx_widen()
  target/riscv: correct the gvec IR called in gen_vec_rsub16_i64()
  target/riscv: fix rsub gvec tcg_assert_listed_vecop assertion
  hw/riscv: Modify MROM size to end at 0x10000
  RISC-V: Support 64 bit start address
  riscv: Add opensbi firmware dynamic support
  RISC-V: Copy the fdt in dram instead of ROM
  riscv: Unify Qemu's reset vector code path
  hw/riscv: virt: Sort the SoC memmap table entries
  MAINTAINERS: Add an entry for OpenSBI firmware

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>