ath10k: move cal data len to hw_params

ath10k_download_cal_dt() compares obtained cal data content length
against QCA988X_CAL_DATA_LEN (2116 bytes). It was written by keeping
qca988x in mind. In fact, cal data length is more chip specific.
To make ath10k_download_cal_dt() more generic and reusable for other
chipsets (like qca4019), cal data length is moved to hw_params.

Signed-off-by: Raja Mani <rmani@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>