This patch fixes cache memory parameter setting for the M32104 target. So
far, its performance seemed to have been degraded due to incorrect cache
parameter setting.
* arch/m32r/boot/setup.S: Set SFR(Special Fuction Registers) region
to be non-cachable explicitly.
* arch/m32r/mm/cache.c: Fix cache flushing routines not to switch off
the M32104 cache.