remove CONFIG_PLATFORM_ARM_* code

Signed-off-by: Hans Ulli Kroll <ulli.kroll@googlemail.com>
remove CONFIG_PLATFORM_TEGRA_* code

Signed-off-by: Hans Ulli Kroll <ulli.kroll@googlemail.com>
remove CONFIG_PLATFORM_MIPS_* code

Signed-off-by: Hans Ulli Kroll <ulli.kroll@googlemail.com>