board: esp32c3: drop sda-gpios and scl-gpios i2c properties

Drop scl and sda gpio properties from two esp32c3 boards. According to
the dts description these are not required, and the corresponding driver
has an explicit check to fail the build if these are defined when the
platform has SOC_I2C_SUPPORT_HW_CLR_BUS defined.

Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>