This is supported by the help text for that option, from the kernel config:
CONFIG_FRAMEBUFFER_CONSOLE_ROTATION:
Enable display rotation for the framebuffer console. This is done
in software and may be significantly slower than a normally oriented
display. Note that the rotation is done at the console level only
such that other users of the framebuffer will remain normally
oriented.
Next time definitely have to read more about the kernel configurations before changing anything.