arm: dts: k3-am654-base-board: Enable wkup_i2c0 across all boot stages

To enable the use of an EEPROM-based board detection scheme we need to
be able to access the I2C bus associated with the EEPROMs across all
3 stages of U-Boot: R5 SPL, A53 SPL, and A53 U-Boot (proper). So go
ahead and add/update the wkup_i2c0 peripheral module DTS definitions
and its associated pinmux node accordingly.

Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>