[ Refactor ] Remove unused function in layer class

[ Refactor ] Remove unused function in layer class

There is no need to exist the initialize(...) in layer class.
This PR removes this unused function.

**Self evaluation:**
1. Build test:	 [X]Passed [ ]Failed [ ]Skipped
2. Run test:	 [X]Passed [ ]Failed [ ]Skipped

Signed-off-by: jijoong.moon <jijoong.moon@samsung.com>