arm64: dts: imx8mm-kontron: Disable pullups for I2C signals on OSM-S i.MX8MM

There are external pullup resistors on the board and due to silicon
errata ERR050080 let's disable the internal ones to prevent any
unwanted behavior in case they wear out.

Fixes: de9618e8 ("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>