This updates the MMC initialization:

  - OMAP_TAG_MMC updates:
      * Re-factor contents into one struct per silicon block
      * Provide information that's useful for SD support, like whether
	the board is wired for 4-wire transfers and what gpio (if any)
	is used to sense the writeprotect slider.
      * Allows for "nonstandard" muxing options, which would mostly
	affect boards using MMC2.
      * Report whether the MMC switch should use the card detect model,
	or the cover switch model.
      * Updated/tested board config only for H2 (not H3 or VoiceBlue).

  - MMC device initialization moved into mach-omap/omap1/device.c and
    out of the MMC driver itself.

  - Removed the "what MMC blocks to configure" option from Kconfig;
    the board-specific MMC tag holds this info (and more).

This new device init hook should be easy to reuse to set up any of the
other integrated devices.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>