MFC: r310309, r310340-310341, r311664, r311793-r311794

o sdhci/mmc: Minor whitespace cleanups

o Add Braswell PCI IDs for Intel Cherryview

o mmc: Accept even lower voltage for Cherryview

And HP x2 210, per DragonFlyBSD 240bd9cd58f8259c12c14a8006837e698.

o In mmcsd_task(), bio_resid was not being set to 0 on a successful read

or write, resulting in random short-read and short-write returns for
requests. Fixing this fixes nominal block I/O via mmcsd(4).

Obtained from: DragonFlyBSD (fd4b97583be1a1e57234713c25f6e81bc0411cb0)

o Add support for Intel Apollo Lake and Bay Trail eMMC PCI controllers.

o Flesh out the support for Intel Braswell eMMC controllers further.

o In sdhci_init_slot(), use the right capability field for determining

the announced bus width based on MMC_CAP_*_BIT_DATA.