phy: freescale: imx8m-pcie: fix pcie link-up instability

phy: freescale: imx8m-pcie: fix pcie link-up instability

[ Upstream commit 3a161017f1de55cc48be81f6156004c151f32677 ]

Leaving AUX_PLL_REFCLK_SEL at its reset default of AUX_IN (PLL clock)
proves to be more stable on the i.MX 8M Mini.

Fixes: 1aa97b002258 ("phy: freescale: pcie: Initialize the imx8 pcie standalone phy driver")
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Richard Zhu <hongxing.zhu@nxp.com>
Link: https://lore.kernel.org/r/20240322130646.1016630-2-marcel@ziswiler.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>