ARM: SAMSUNG: Remove hardware.h inclusion

The contents of this header file are not referenced anywhere in the
included .c files except in devs.c. Remove its inclusion. For devs.c,
explicitly include sizes.h header for SZ_* macros.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>