armv8: kconfig: Fix some platforms incorrect I2C clock divider

By default, i2c input clock is platform clk / 2, but some of the
platform of i2c clock divider does not meet this kind of circumstance,
so alone to set default values for these platforms.

Signed-off-by: Chuanhua Han <chuanhua.han@nxp.com>
Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>