ARM: 7339/1: amba/serial.h: Include types.h for resolving dependency of type bool

serial.h uses bool, but its definition is missing, as it doesn't include
types.h. Fix this by including types.h

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