Multiple peripherals in SPEAr share common hardware interrupt lines.
This patch adds support for a shared irq layer, which registers hardware
irqs by itself and exposes virtual irq numbers to peripherals.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Reviewed-by: NLinus Walleij <linux.walleij@stericsson.com>
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>