phy: rockchip-pcie: Properly disable TEST_WRITE strobe signal

pcie_conf is used to touch TEST_WRITE strobe signal. This signal should
be enabled, a little time waited, and then disabled. Current code clearly
was copy-pasted and never disables the strobe signal. Adjust the define.
While at it, remove PHY_CFG_RD_MASK which has been unused since
64cdc036 ("phy: rockchip-pcie: remove unused phy_rd_cfg function").

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>
Link: https://lore.kernel.org/r/d514d5d5627680caafa8b7548cbdfee4307f5440.1751322015.git.geraldogabriel@gmail.com


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