Fix: alignment problems on targets not supporting unaligned access.

Accessing floats, doubles and 64 bit int at unaligned addresses is not
supported on all configurations of arm processors and if it is it's
emulated and slow. This patch replaces direct assignments with memcpy.

Signed-off-by: Fredrik Markström <fredrik.markstrom@gmail.com>
Signed-off-by: Roy Li <rongqing.li@windriver.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>