ath10k: expose hif ops for ahb

Like how pci.c exposes hif ops for the bus specific operation,
expose similar hif ops table for ahb with all required functions
linked to it. Many ath10k_pci_* functions are reused here in hif ops
table. If something is not sharable, new functions are added for ahb
and linked to hif ops table.

Finally, make ath10k_ahb_probe/remove() to perform what is expected
out of it.

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