i2c: xgene-slimpro: Migrate to use generic PCC shmem related macros

Use the newly defined common and generic PCC shared memory region
related macros in this driver to replace the locally defined ones.

Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Wolfram Sang <wsa@kernel.org>
Link: https://lore.kernel.org/r/20230927-pcc_defines-v2-2-0b8ffeaef2e5@arm.com


Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>