arm: cortex-a9: Fix cache-line size and associativity

For A9, The cache associativity is 4 and the lines size is 32B.
Self identify in CCSIDR accordingly. Cache size remains at 16k.

QEMU doesn't emulate caches, but we should still report the correct
cache-line size to the guest. Some guests (like u-boot) complain if
the cache-line size mismatches a requested flush or invalidate
operation.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: 1de6bd40155a1d2f2e93e24b1b1d1d677a432641.1408346233.git.peter.crosthwaite@xilinx.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
