arm64: dts: imx8mm-kontron: Disable pullups for onboard UART signals on BL OSM-S...

arm64: dts: imx8mm-kontron: Disable pullups for onboard UART signals on BL OSM-S board

[ Upstream commit c6d9b5672a0e2c4b1079a50d2fc8780c40cfd3eb ]

These signals are actively driven by the SoC or by the onboard
transceiver. There's no need to enable the internal pull resistors
and due to silicon errata ERR050080 let's disable the internal ones
to prevent any unwanted behavior in case they wear out.

Fixes: de9618e84f76 ("arm64: dts: Add support for Kontron SL/BL i.MX8MM OSM-S")
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>