gpio: Include linux/gpio.h instead of asm/gpio.h

Most arches have an asm/gpio.h that merely includes linux/gpio.h.  The
others select ARCH_HAVE_CUSTOM_GPIO_H, and when that's selected,
linux/gpio.h includes asm/gpio.h.

Therefore, code should include linux/gpio.h instead of including asm/gpio.h
directly.

Remove includes of asm/gpio.h, adding an include of linux/gpio.h when
necessary.

This is a follow-on to 7563bbf89d06 ("gpiolib/arches: Centralise
bolierplate asm/gpio.h").

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/arch/blackfin/mach-bf538/boards/ezkit.c b/arch/blackfin/mach-bf538/boards/ezkit.c
index ae2fcbb..c423af3 100644
--- a/arch/blackfin/mach-bf538/boards/ezkit.c
+++ b/arch/blackfin/mach-bf538/boards/ezkit.c
@@ -15,9 +15,9 @@
 #include <linux/spi/flash.h>
 #include <linux/irq.h>
 #include <linux/interrupt.h>
+#include <linux/gpio.h>
 #include <asm/bfin5xx_spi.h>
 #include <asm/dma.h>
-#include <asm/gpio.h>
 #include <asm/nand.h>
 #include <asm/portmux.h>
 #include <asm/dpmc.h>