opal: Cache chipTOD control register values.
opal: Cache chipTOD control register values.

Cache chiptod control register values during chiptod initialization and
whenever there is a change in topology configuration. In subsequent patches,
these saved values will be used to recover from parity errors on respective
chiptod control registers.

This patch caches values of following registers:

- Master Path control register (0x00040000)
- Primary Port-0 control register (0x00040001)
- Primary Port-1 control register (0x00040002)
- Secondary Port-0 control register (0x00040003)
- Secondary Port-1 control register (0x00040004)
- Slave Path control register (0x00040005)
- Internal Path control register (0x00040006)
- Primary/secondary master/slave control register (0x00040007)
- Chip control register (0x00040010)

Signed-off-by: Mahesh Salgaonkar <6a890e1065a1d4e8df9dcf1d9a2c9c740bbcf8aa@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

qemu/skiboot,legoater/skiboot,qemu/skiboot,ddstreet/skiboot,shenki/skiboot,ddstreet/skiboot,legoater/skiboot,apopple/skiboot,shenki/skiboot,shenki/skiboot,stewart-ibm/skiboot,mikey/skiboot,shenki/skiboot,stewart-ibm/skiboot,csmart/skiboot,qemu/skiboot,open-power/skiboot,mikey/skiboot,legoater/skiboot,stewart-ibm/skiboot,apopple/skiboot,open-power/skiboot,open-power/skiboot,csmart/skiboot,apopple/skiboot,open-power/skiboot,legoater/skiboot,qemu/skiboot,open-power/skiboot,shenki/skiboot,csmart/skiboot,ddstreet/skiboot,mikey/skiboot,legoater/skiboot,qemu/skiboot