ARM: 6003/1: removing compilation warning from pl061.h

pl061.h is using u8 type. including <linux/types.h> in pl061.h to avoid
warning.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>