ARM: 9415/1: amba: Add dev_is_amba() function and export it for modules

Add dev_is_amba() function to determine
whether the device is a AMBA device.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>