ARM: sh7372: fix cache clean / invalidate order

According to the Cortex A8 TRM the L2 cache should be first cleaned and
then disabled. Fix the swapped order on sh7372.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>