Merge remote-tracking branch 'remotes/philmd-gitlab/tags/sparc-next-20200609' into staging

SPARC patches

HW:
- Use UNIMP device instead of EMPTY_SLOT
- Make EMPTY_SLOT similar to UNIMP device
- Map UART devices unconditionally
- Pair of fixes for AHB PnP
- Add trace events to AHB PnP

TCG:
- Improve exception logging

CI:
- https://gitlab.com/philmd/qemu/-/pipelines/154231191
- https://travis-ci.org/github/philmd/qemu/builds/696321130



# gpg: Signature made Tue 09 Jun 2020 08:24:09 BST
# gpg:                using RSA key FAABE75E12917221DCFD6BB2E3E32C2CDEADC0DE
# gpg: Good signature from "Philippe Mathieu-Daudé (F4BUG) <f4bug@amsat.org>" [full]
# Primary key fingerprint: FAAB E75E 1291 7221 DCFD  6BB2 E3E3 2C2C DEAD C0DE

* remotes/philmd-gitlab/tags/sparc-next-20200609:
  target/sparc/int32_helper: Extract and use excp_name_str()
  target/sparc/int32_helper: Remove DEBUG_PCALL definition
  hw/timer/grlib_gptimer: Display frequency in decimal
  hw/misc/grlib_ahb_apb_pnp: Add trace events on read accesses
  hw/misc/grlib_ahb_apb_pnp: Fix AHB PnP 8-bit accesses
  hw/misc/grlib_ahb_apb_pnp: Avoid crash when writing to AHB PnP registers
  hw/sparc64/niagara: Remove duplicated NIAGARA_UART_BASE definition
  hw/sparc64/niagara: Map the UART device unconditionally
  hw/sparc/leon3: Map the UART device unconditionally
  hw/misc/empty_slot: Name the slots when created
  hw/misc/empty_slot: Move the 'hw/misc' and cover in MAINTAINERS
  hw/misc/empty_slot: Convert debug printf() to trace event
  hw/misc/empty_slot: Add a 'name' qdev property
  hw/misc/empty_slot: Convert 'size' field as qdev property
  hw/misc/empty_slot: Lower address space priority
  hw/sparc/sun4m: Use UnimplementedDevice for I/O devices

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