Merge remote-tracking branch 'remotes/philmd-gitlab/tags/sd-next-20200821' into staging

Merge remote-tracking branch 'remotes/philmd-gitlab/tags/sd-next-20200821' into staging

SD/MMC patches

- Convert legacy SD host controller to the SDBus API
- Move legacy API to a separate "sdcard_legacy.h" header
- Introduce methods to access multiple bytes on SDBus data lines
- Fix 'switch function' group location
- Fix SDSC maximum card size (2GB)

CI jobs result:
  https://gitlab.com/philmd/qemu/-/pipelines/180605963

# gpg: Signature made Fri 21 Aug 2020 18:27:50 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/sd-next-20200821: (23 commits)
  hw/sd: Correct the maximum size of a Standard Capacity SD Memory Card
  hw/sd: Fix incorrect populated function switch status data structure
  hw/sd: Use sdbus_read_data() instead of sdbus_read_byte() when possible
  hw/sd: Add sdbus_read_data() to read multiples bytes on the data line
  hw/sd: Use sdbus_write_data() instead of sdbus_write_byte when possible
  hw/sd: Add sdbus_write_data() to write multiples bytes on the data line
  hw/sd: Rename sdbus_read_data() as sdbus_read_byte()
  hw/sd: Rename sdbus_write_data() as sdbus_write_byte()
  hw/sd: Rename read/write_data() as read/write_byte()
  hw/sd: Move sdcard legacy API to 'hw/sd/sdcard_legacy.h'
  hw/sd/sdcard: Make sd_data_ready() static
  hw/sd/pl181: Replace disabled fprintf()s by trace events
  hw/sd/pl181: Do not create SD card within the SD host controller
  hw/sd/pl181: Expose a SDBus and connect the SDCard to it
  hw/sd/pl181: Use named GPIOs
  hw/sd/pl181: Add TODO to use Fifo32 API
  hw/sd/pl181: Rename pl181_send_command() as pl181_do_command()
  hw/sd/pl181: Replace fprintf(stderr, "*\n") with error_report()
  hw/sd/milkymist: Do not create SD card within the SD host controller
  hw/sd/milkymist: Create the SDBus at init()
  ...

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