This commit does the following updates.
1. Split the common cache access from cpu.c into lib folder.
2. Rename the following cache api to adapt common.h
- dcache_flush_rang -> flush_dcache_rang
- icache_inval_range -> invalidate_icache_range
3. Add invalidate_dcache_range
Signed-off-by: Macpaul Lin <macpaul@gmail.com>
