Merge remote-tracking branch 'remotes/philmd-gitlab/tags/pflash-next-20190716' into staging

pflash-next patches for v4.1.0-rc1

Trivial pflash fixes for rc1.

# gpg: Signature made Tue 16 Jul 2019 16:59:53 BST
# gpg:                using RSA key E3E32C2CDEADC0DE
# 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/pflash-next-20190716:
  hw/block/pflash_cfi01: Start state machine as READY to accept commands
  hw/block/pflash_cfi02: Explicit switch fallthrough for ERASE commands

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