cxl/test: remove unused mock function for cxl_rcd_component_reg_phys()

cxl/test: remove unused mock function for cxl_rcd_component_reg_phys()

Since commit 733b57f262b0 ("cxl/pci: Early setup RCH dport component registers from RCRB")
is not necessary under mocking tests.

[ dj: Fixup commit representation flagged by checkpatch. ]
[ dj: Ammend subject line to indicate which function. ]

Signed-off-by: Alejandro Lucero <alucerop@amd.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>> ---
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://patch.msgid.link/20251118182202.2083244-1-alejandro.lucero-palau@amd.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>