Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20180222' into staging

 * New "raspi3" machine emulating RaspberryPi 3
 * Fix bad register definitions for VMIDR and VMPIDR (which caused
   assertions for 64-bit guest CPUs with EL2 on big-endian hosts)
 * hw/char/stm32f2xx_usart: fix TXE/TC bit handling
 * Fix ast2500 protection register emulation
 * Lots of SD card emulation cleanups and bugfixes

# gpg: Signature made Thu 22 Feb 2018 15:18:53 GMT
# gpg:                using RSA key 3C2525ED14360CDE
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>"
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>"
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>"
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20180222: (32 commits)
  sdcard: simplify SD_SEND_OP_COND (ACMD41)
  sdcard: simplify SEND_IF_COND (CMD8)
  sdcard: warn if host uses an incorrect address for APP CMD (CMD55)
  sdcard: check the card is in correct state for APP CMD (CMD55)
  sdcard: handles more commands in SPI mode
  sdcard: use a more descriptive label 'unimplemented_spi_cmd'
  sdcard: handle the Security Specification commands
  sdcard: handle CMD54 (SDIO)
  sdcard: use the registerfields API for the CARD_STATUS register masks
  sdcard: use the correct masked OCR in the R3 reply
  sdcard: simplify using the ldst API
  sdcard: remove commands from unsupported old MMC specification
  sdcard: clean the SCR register and add few comments
  sdcard: fix the 'maximum data transfer rate' to 25MHz
  sdcard: update the CSD CRC register regardless the CSD structure version
  sdcard: Don't always set the high capacity bit
  sdcard: use the registerfields API to access the OCR register
  sdcard: use G_BYTE from cutils
  sdcard: define SDMMC_CMD_MAX instead of using the magic '64'
  sdcard: add more trace events
  ...

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