Make the twl4030 core create a platform device to which its
GPIO code will bind, with platform_data used to configure
board-specific behaviors and configuration.

Update the twl4030 GPIO code:

  - Morph its gpio function code into a platform driver.

  - Move away from IRQ (and GPIO) numbers hard-wired in headers.

  - Hook up the twl4030 GPIO code to gpiolib.

  - Start phasing out the older TWL-specific calls ... currently
    those are used only by arch/arm/mach-omap2/hsmmc.c setup code.

  - Use a mutex for locking, not a binary semaphore.

NOTE:  more patches pending:  (a) this doesn't use pdata->pullups
to initialize (currently hsmmc code always sets GPIO-0 pullup even
if the board has an external pullup);  (b) there's a new gpio
request/free hook forthcoming in 2.6.28, which this should use;
(c) likewise there's a new gpio_to_irq() hook; (d) the irq_chip
set_type() mechanism needs to be supported; (e) needs to move over
to drivers/gpio; (f) upcoming threaded IRQ infrastructure should
be used, when that merges.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>