ARM: l2c: realview: improve commentry about the L2 cache requirements

Add better commentry about the L2 cache requirements on these platforms.
Unfortunately, the auxiliary control register is not pre-set to indicate
the correct cache parameters, so we have to manually program these.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --cc arch/arm/mach-realview/realview_eb.c
Simple merge

diff --cc arch/arm/mach-realview/realview_pb1176.c
Simple merge

diff --cc arch/arm/mach-realview/realview_pb11mp.c
Simple merge