Merge remote-tracking branch 'remotes/alistair/tags/pull-riscv-to-apply-20201217...

Merge remote-tracking branch 'remotes/alistair/tags/pull-riscv-to-apply-20201217-1' into staging

A collection of RISC-V improvements:
 - Improve the sifive_u DTB generation
 - Add QSPI NOR flash to Microchip PFSoC
 - Fix a bug in the Hypervisor HLVX/HLV/HSV instructions
 - Fix some mstatus mask defines
 - Ibex PLIC improvements
 - OpenTitan memory layout update
 - Initial steps towards support for 32-bit CPUs on 64-bit builds

# gpg: Signature made Fri 18 Dec 2020 05:59:42 GMT
# 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-20201217-1: (23 commits)
  riscv/opentitan: Update the OpenTitan memory layout
  hw/riscv: Use the CPU to determine if 32-bit
  target/riscv: cpu: Set XLEN independently from target
  target/riscv: csr: Remove compile time XLEN checks
  target/riscv: cpu_helper: Remove compile time XLEN checks
  target/riscv: cpu: Remove compile time XLEN checks
  target/riscv: Specify the XLEN for CPUs
  target/riscv: Add a riscv_cpu_is_32bit() helper function
  target/riscv: fpu_helper: Match function defs in HELPER macros
  hw/riscv: sifive_u: Remove compile time XLEN checks
  hw/riscv: spike: Remove compile time XLEN checks
  hw/riscv: virt: Remove compile time XLEN checks
  hw/riscv: boot: Remove compile time XLEN checks
  riscv: virt: Remove target macro conditionals
  riscv: spike: Remove target macro conditionals
  target/riscv: Add a TYPE_RISCV_CPU_BASE CPU
  hw/riscv: Expand the is 32-bit check to support more CPUs
  intc/ibex_plic: Clear interrupts that occur during claim process
  target/riscv: Fix definition of MSTATUS_TW and MSTATUS_TSR
  target/riscv: Fix the bug of HLVX/HLV/HSV
  ...

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