[enco] Emit global weight data as a binary file (#1741)

[enco] Emit global weight data as a binary file (#1741)

With this commit, C++ code that enco generates no longer includes an
initializer for global weight data.

Instead, enco generates .bin file, and embed this data into an
executable through corresponding asm file.

This change significantly reduces the overhead of C++ code generation
and its compilation.

Signed-off-by: Jonghyun Park <jh1302.park@samsung.com>