iwlwifi: a000: fix memory offsets and lengths

Memory offsets and lengths for A000 HW is different
than currently specified.

Fixes: e34d975e ("iwlwifi: Add a000 HW family support")
Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>