cxl/pci: cxl_dport_map_rch_aer() cleanup

cxl/pci: cxl_dport_map_rch_aer() cleanup

cxl_dport_map_ras() is used to map CXL RAS capability, the RCH AER
capability should not be mapped in the function but should mapped in
cxl_dport_init_ras_reporting(). Moving cxl_dport_map_ras() out of
cxl_dport_map_ras() and into cxl_dport_init_ras_reporting().

In cxl_dport_init_ras_reporting(), the AER capability position in RCRB
will be located but the position is only used in
cxl_dport_map_rch_aer(), getting the position in cxl_dport_map_rch_aer()
rather than cxl_dport_init_ras_reporting() is more reasonable and makes
the code clearer.

Besides, some local variables in cxl_dport_map_rch_aer() are
unnecessary, remove them to make the function more concise.

Signed-off-by: Li Ming <ming4.li@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://patch.msgid.link/20240830061308.2327065-2-ming4.li@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>