Add eps parameter to QAT quantization config functions

[psiddh]

Summary:
D90093073 introduced an eps parameter to PTQ quantization config functions but missed adding it to the QAT equivalents (get_8a8w_qnn_qat_config, get_16a4w_qnn_qat_config, get_qat_per_channel_quant_config). This caused test_qnn_backend_linear_qat to fail because ModuleQConfig.__post_init__ now passes eps=self.eps to all config functions, but the QAT functions didn't accept this parameter.

This change adds the eps parameter to these QAT config functions and properly applies it to all observers (activation, weight, and bias) to maintain consistency with the PTQ functions.

Reviewed By: SS-JIA

Differential Revision: D90123723

cc @cccclai @winskuo-quic @shewu-quic @haowhsu-quic @DannyYuyang-quic @cbilgin

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As of commit 20554fc with merge base 419427c ():

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[meta-codesync]

@psiddh has exported this pull request. If you are a Meta employee, you can view the originating Diff in D90123723.

[SS-JIA]

Review automatically exported from Phabricator review in Meta.

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