Merge remote-tracking branch 'remotes/mcayland/tags/qemu-sparc-20210412' into staging

qemu-sparc queue

# gpg: Signature made Mon 12 Apr 2021 23:13:12 BST
# gpg:                using RSA key CC621AB98E82200D915CC9C45BC2C56FAE0F321F
# gpg:                issuer "mark.cave-ayland@ilande.co.uk"
# gpg: Good signature from "Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>" [full]
# Primary key fingerprint: CC62 1AB9 8E82 200D 915C  C9C4 5BC2 C56F AE0F 321F

* remotes/mcayland/tags/qemu-sparc-20210412:
  tests/qtest: add tests for am53c974 device
  esp: ensure that do_cmd is set to zero before submitting an ESP select command
  esp: don't reset async_len directly in esp_select() if cancelling request
  esp: don't overflow cmdfifo if TC is larger than the cmdfifo size
  esp: don't overflow cmdfifo in get_cmd()
  esp: don't underflow cmdfifo in do_cmd()
  esp: ensure cmdfifo is not empty and current_dev is non-NULL
  esp: introduce esp_fifo_pop_buf() and use it instead of fifo8_pop_buf()
  esp: consolidate esp_cmdfifo_pop() into esp_fifo_pop()
  esp: consolidate esp_cmdfifo_push() into esp_fifo_push()
  esp: rework write_response() to avoid using the FIFO for DMA transactions
  esp: always check current_req is not NULL before use in DMA callbacks
  esp: fix setting of ESPState mig_version_id when launching QEMU with -S option

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