CANN: Support ext_factor in rope

[hipudding]

Make sure to read the contributing guidelines before submitting a PR

./bin/test-backend-ops -b CANN0 -o ROPE
Testing 3 devices
Backend 1/3: CANN0
Device description: Ascend910B4
Device memory: 30196 MB (29802 MB free)
11837/11837 tests passed
Backend CANN0: OK
Backend 2/3: CANN1
Skipping
Backend 3/3: CPU
Skipping
3/3 backends passed
OK

Test it with DeepSeek-V2-Lite

llama_perf_sampler_print:    sampling time =     150.96 ms /   810 runs   (    0.19 ms per token,  5365.73 tokens per second)
llama_perf_context_print:        load time =   20965.59 ms
llama_perf_context_print: prompt eval time =     247.80 ms /    17 tokens (   14.58 ms per token,    68.60 tokens per second)
llama_perf_context_print:        eval time =   18359.62 ms /   792 runs   (   23.18 ms per token,    43.14 tokens per second)
llama_perf_context_print:       total time =   19236.89 ms /   809 tokens
llama_perf_context_print:    graphs reused =        789

[noemotiovon]

LGTM!