fix: Remove llama-kv-cache.*

The kv cache hierarchy was squashed so that now all of the llama-kv-cache-*
implementations inherit directly from llama_memory_i and there is no
intermediary llama_kv_cache base class.

ggml-org/llama.cpp#14006

Branch: GraniteFour

Signed-off-by: Gabe Goodhart <ghart@us.ibm.com>

Author: gabe-l-hart