Merge remote-tracking branch 'remotes/philmd-gitlab/tags/sdmmc-20210124' into staging

SD/MMC patches

- Various improvements for SD cards in SPI mode (Bin Meng)

# gpg: Signature made Sun 24 Jan 2021 19:16:55 GMT
# 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/sdmmc-20210124:
  hw/sd: sd.h: Cosmetic change of using spaces
  hw/sd: ssi-sd: Use macros for the dummy value and tokens in the transfer
  hw/sd: ssi-sd: Fix the wrong command index for STOP_TRANSMISSION
  hw/sd: ssi-sd: Add a state representing Nac
  hw/sd: ssi-sd: Suffix a data block with CRC16
  util: Add CRC16 (CCITT) calculation routines
  hw/sd: sd: Drop sd_crc16()
  hw/sd: sd: Support CMD59 for SPI mode
  hw/sd: ssi-sd: Fix incorrect card response sequence

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