ARM: EXYNOS: Remove unused board files

Since commit 383ffda2

 ARM: EXYNOS: no more support non-DT for EXYNOS SoCs
all non-DT Exynos board files are not used anymore. This patch removes
them.

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