The Raspberry Pi 4 SDHCI hardware seems to automatically issue CMD12
after multiblock reads even when ACMD12 is disabled. This triggers
spurious interrupts after the data transfer is done with the following
message:

  mmc1: Got data interrupt 0x00000002 even though no data operation was in progress.
  mmc1: sdhci: ============ SDHCI REGISTER DUMP ===========
  mmc1: sdhci: Sys addr:  0x00000000 | Version:  0x00001002
  mmc1: sdhci: Blk size:  0x00007200 | Blk cnt:  0x00000000
  mmc1: sdhci: Argument:  0x00000000 | Trn mode: 0x00000033
  mmc1: sdhci: Present:   0x1fff0000 | Host ctl: 0x00000017
  mmc1: sdhci: Power:     0x0000000f | Blk gap:  0x00000080
  mmc1: sdhci: Wake-up:   0x00000000 | Clock:    0x00000107
  mmc1: sdhci: Timeout:   0x00000000 | Int stat: 0x00000000
  mmc1: sdhci: Int enab:  0x03ff100b | Sig enab: 0x03ff100b
  mmc1: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000000
  mmc1: sdhci: Caps:      0x45ee6432 | Caps_1:   0x0000a525
  mmc1: sdhci: Cmd:       0x00000c1a | Max curr: 0x00080008
  mmc1: sdhci: Resp[0]:   0x00000b00 | Resp[1]:  0x00edc87f
  mmc1: sdhci: Resp[2]:   0x325b5900 | Resp[3]:  0x00400e00
  mmc1: sdhci: Host ctl2: 0x00000001
  mmc1: sdhci: ADMA Err:  0x00000000 | ADMA Ptr: 0xf3025208
  mmc1: sdhci: ============================================

Enable SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12 to enable ACMD12 on multiblock
reads and suppress the spurious interrupts.

Fixes: f84e411c ("mmc: sdhci-iproc: Add support for emmc2 of the BCM2711")
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Matthias Brugger <mbrugger@suse.com>
Acked-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>