[PATCH] Remove OSK/Mistral and Innovator old touchscreen support

Remove OSK/Mistral and Innovator support for the old OMAP-specfic
touchscreen framework; both of those board should be able to use
the new SPI framework with the ads7846 touchscreen driver that's
now in the upstream kernels.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>