ARM: 6793/1: SPEAr: Remove unused *_SIZE macros from spear*.h files

Now we used standard SZ_* macros instead of self defined *_SIZE macros. This
patch removes all such unused *_SIZE macros for spear3xx & 6xx.

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