sev is used to send wakeup event to other cores in ARMv6K and above.
This has been moved from platform specific part to standard common
ARM header file (asm/system.h). Also introduced wfi() and wfe().
Signed-off-by: NShiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>