This patch eliminates the global gpio_lock, and implements a per-controller
lock instead.  This also switches to irqsave/irqrestore locks in case gpios
are manipulated in isr.
Signed-off-by: NCyril Chemparathy <cyril@ti.com>
Tested-by: NSandeep Paulraj <s-paulraj@ti.com>
Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>