Make block-cache.c be common interface

To use block-cache.c be common cache interface, we need to add
some parameter to identify cache's type.

Define a struct named BlockTableType, pass BlockTableType and
table size parameters to block cache initialization function.

v17-v18:
1) move struct to source file.
2) cluster_size->table_size.

Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>