ath10k: improve the firmware download time for QCA9377

QCA9377 is the family of QCA61x4 which shared the same procedure
to enable the hardware clock that could improve the firmware download time.

Signed-off-by: Ryan Hsu <ryanhsu@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>