ARM: dts: imx: ba16: Add correct PCIe Tx Values

Utilize the new PCIe Tx configuration to properly support the correct
values.

Signed-off-by: Justin Waters <justin.waters@timesys.com>
Signed-off-by: Akshay Bhat <akshay.bhat@timesys.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>