uboot-imx

T2080QDS/PCIe: Soft Reset PCIe on T2080QDS for down-training issue

T2080QDS PEX1/Slot#1 will down-train from x4 to x2,
with SRDS_PRTCL_S1 = 0x66 and SRDS_PRTCL_S2 = 0x15.
Soft reset PCIe can fix this issue.

Signed-off-by: Zhao Qiang <B45475@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>