ARM: 7362/1: AMBA: Add module_amba_driver() helper macro for amba_driver

For simple modules that contain a single amba_driver without any
additional setup code then ends up being a block of duplicated
boilerplate. This patch adds a new macro, module_amba_driver(),
which replaces the module_init()/module_exit() registrations with
template functions.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>