sdhci: Advertise 2.0v supply on SDIO host controller

sdhci: Advertise 2.0v supply on SDIO host controller

BugLink: http://bugs.launchpad.net/bugs/1763366
[ Upstream commit 2a609abe71ca59e4bd7139e161eaca2144ae6f2e ]

On Intel Edison the Broadcom Wi-Fi card, which is connected to SDIO,
requires 2.0v, while the host, according to Intel Merrifield TRM,
supports 1.8v supply only.

The card announces itself as

  mmc2: new ultra high speed DDR50 SDIO card at address 0001

Introduce a custom OCR mask for SDIO host controller on Intel Merrifield
and add a special case to sdhci_set_power_noreg() to override 2.0v supply
by enforcing 1.8v power choice.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>