console: Kconfig: Update for recent changes
console: Kconfig: Update for recent changes

Buffer sizes aren't required to be power of 2 for a while. Describe
that by setting buffers sizes to 0, one can get non interrupt driven
operation.

Signed-off-by: Paul Sokolovsky <35cb557f011771c94f127d6fef99f804b62203f5@linaro.org>

zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,Vudentz/zephyr,ldts/zephyr,galak/zephyr,Vudentz/zephyr,punitvara/zephyr,Vudentz/zephyr,ldts/zephyr,nashif/zephyr,nashif/zephyr,nashif/zephyr,finikorg/zephyr,nashif/zephyr,nashif/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,galak/zephyr,explora26/zephyr,explora26/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,ldts/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,finikorg/zephyr,punitvara/zephyr,explora26/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,punitvara/zephyr,galak/zephyr,ldts/zephyr,punitvara/zephyr,punitvara/zephyr