ARM: EXYNOS: Remove remaining dead code after non-DT support removal

This patch removes remaining small bits of unused code that was left
after removing non-DT support.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>