[ARM] 4495/1: iop: combined watchdog timer driver for iop3xx and iop13xx

In order for this driver to be shared across the iop architectures the
iop3xx and iop13xx header files are modified to present a common interface
for the iop_wdt driver.

Details:
* iop13xx supports disabling the timer while iop3xx does not.  This requires
  a few 'compatibility' definitions in include/asm-arm/hardware/iop3xx.h to
  preclude adding #ifdef CONFIG_ARCH_IOP13XX blocks to the driver code.
* The heartbeat interval is derived from the internal bus clock rate, so this
  this patch also exports the tick rate to the iop_wdt driver.

Cc: Curt Bruns <curt.e.bruns@intel.com>
Cc: Peter Milne <peter.milne@d-tacq.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/char/watchdog/Makefile b/drivers/char/watchdog/Makefile
index 3907ec0..bdb9d5e 100644
--- a/drivers/char/watchdog/Makefile
+++ b/drivers/char/watchdog/Makefile
@@ -35,6 +35,7 @@
 obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o
 obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_wdt.o
 obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o
+obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o
 
 # AVR32 Architecture
 obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o