phy: rockchip-pcie: remove unused phy_rd_cfg function

clang with W=1 reports
drivers/phy/rockchip/phy-rockchip-pcie.c:122:19: error:
  unused function 'phy_rd_cfg' [-Werror,-Wunused-function]
static inline u32 phy_rd_cfg(struct rockchip_pcie_phy *rk_phy,
                  ^
This function is not used, so remove it.

Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20230321122503.1783311-1-trix@redhat.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>