ARM: 6935/1: SPEAR3xx: Rename register/irq defines to remove naming conflicts

Prefix register and irq defintions to remove naming conflicts between
the three SPEAr3xx platforms.

Reviewed-by: Stanley Miao <stanley.miao@windriver.com>
Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>