drivers: sensors: bma4xx: add I2C_RTIO Kconfig for I2C

Since #83575 bma4xx driver relies on RTIO to work. This means that
CONFIG_I2C_RTIO should be defined together with CONFIG_I2C in the
Kconfig, otherwise I2C_DT_IODEV_DEFINE() won't be available at
build time.

Signed-off-by: Valerio Setti <vsetti@baylibre.com>