Avoid to define gpio_to_irq() and irq_to_gpio() for potential name
confliction since multiple architecture will be built together.
Signed-off-by: NHaojian Zhuang <haojian.zhuang@marvell.com>

The <mach/gpio.h> file is included from upper directories
and deal with generic GPIO and gpiolib stuff. Break out the
platform and driver specific defines and functions into its own
header file.

Cc: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Rather than marking the mach/gpio.h header files which want to use the
trivial GPIOLIB implementation, mark those which do not want to use it
instead.  This means that by default, you get the trivial implementation
and only have to do something extra if you need to.  This should
encourage the use of the trivial default implementation.

As an additional bonus, several gpio.h header files become empty.
Acked-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: NJamie Iles <jamie@jamieiles.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NLennert Buytenhek <buytenh@secretlab.ca>

1. add common GPIO handling code into [arch/arm/plat-pxa]

2. common code in <mach/gpio.h> moved into <plat/gpio.h>, new processors
   should implement its own <mach/gpio.h>, provide the following required
   definitions and '#include <plat/gpio.h>' in the end:

   - GPIO_REGS_VIRT for mapped virtual address of the GPIO registers'
     physical I/O memory

   - macros of GPLR(), GPSR(), GPDR() for constant optimization for
     functions gpio_{set,get}_value() (so that bit-bang code can still
     have tolerable performance)

   - NR_BUILTIN_GPIO for the number of onchip GPIO

   - definitions of __gpio_is_inverted() and __gpio_is_occupied(), they
     can be either macros or inlined functions
Signed-off-by: NEric Miao <eric.miao@marvell.com>