PCI: rcar: Remove redundant config accessor register number checks

The PCI core will have already checked the configuration register address
before calling the {read|write}() methods; so don't check it again in these
methods.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Phil Edworthy <phil.edworthy@renesas.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>