ice: rename TS_LL_READ* macros to REG_LL_PROXY_H_*

The TS_LL_READ macros are used as part of the low latency Tx timestamp
interface. A future firmware extension will add support for performing PHY
timer updates over this interface. Using TS_LL_READ as the prefix for these
macros will be confusing once the interface is used for other purposes.

Rename the macros, using the prefix REG_LL_PROXY_H, to better clarify that
this is for the low latency interface.
Additionally add macros for PF_SB_ATQBAH and PF_SB_ATQBAL registers to
better clarify content of this registers as PF_SB_ATQBAH contain low
part of Tx timestamp

Co-developed-by: Karol Kolacinski <karol.kolacinski@intel.com>
Signed-off-by: Karol Kolacinski <karol.kolacinski@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Milena Olech <milena.olech@intel.com>
Signed-off-by: Anton Nadezhdin <anton.nadezhdin@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>