clk: rs9: Fix suspend/resume

clk: rs9: Fix suspend/resume

Disabling the cache in commit 2ff4ba9e3702 ("clk: rs9: Fix I2C accessors")
without removing cache synchronization in resume path results in a
kernel panic as map->cache_ops is unset, due to REGCACHE_NONE.
Enable flat cache again to support resume again. num_reg_defaults_raw
is necessary to read the cache defaults from hardware. Some registers
are strapped in hardware and cannot be provided in software.

Fixes: 2ff4ba9e3702 ("clk: rs9: Fix I2C accessors")
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20230310074940.3475703-1-alexander.stein@ew.tq-group.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>