ARC: Cache: Add missing cache cleanup before cache disable

ARC: Cache: Add missing cache cleanup before cache disable

Add missing cache cleanup before cache disable:
 * Flush and invalidate L1 D$ before disabling. Flush and invalidate
   SLC before L1 D$ disabling (as it will be bypassed for data)
   Otherwise we can lose some data when we disable L1 D$ if this data
   isn't flushed to next level cache. Or we can get wrong data if L1 D$
   has some entries after enable which we modified when the L1 D$ was
   disabled.
 * Invalidate L1 I$ before disabling. Otherwise we can execute wrong
   instructions after L1 I$ enable if we modified any code when
   L1 I$ was disabled.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>