Fix: incorrect import paths for attention processors

[hahminlew]

This PR fixes incorrect import statements in models.py.
Previously, the code attempted to import attention processor classes from src.ip_adapter.*, which caused ModuleNotFoundError when running the project.

Changes:
Updated imports to reference the correct top-level modules:

from src.attention_processor import AttnProcessor2_0 as AttnProcessor
from src.attention_processor import IPAttnProcessor2_0 as IPAttnProcessor
from src.mask_attention_processor import IPAttnProcessor2_0WithIPMaskController

Reason
The attention processor modules are located directly under src/, not under src/ip_adapter/. This fix ensures the project can be executed without import errors.

Test
Verified that the project runs after this change without raising ModuleNotFoundError.