wifi: ath12k: hal: convert offset macros to functions

After previous patch checkpatch was giving warnings:

drivers/net/wireless/ath/ath12k/hal.h:158: Macro argument reuse 'ab' - possible side-effects?
drivers/net/wireless/ath/ath12k/hal.h:160: Macro argument reuse 'ab' - possible side-effects?
drivers/net/wireless/ath/ath12k/hal.h:162: Macro argument reuse 'ab' - possible side-effects?
drivers/net/wireless/ath/ath12k/hal.h:164: Macro argument reuse 'ab' - possible side-effects?
drivers/net/wireless/ath/ath12k/hal.h:173: Macro argument reuse 'ab' - possible side-effects?
drivers/net/wireless/ath/ath12k/hal.h:175: Macro argument reuse 'ab' - possible side-effects?
drivers/net/wireless/ath/ath12k/hal.h:177: Macro argument reuse 'ab' - possible side-effects?
drivers/net/wireless/ath/ath12k/hal.h:179: Macro argument reuse 'ab' - possible side-effects?

To fix those convert the macros into functions. As it was difficult to use
struct ath12k_base within hal.h, core.h was already including hal.h so
including back core.h would not work, move the functions also to hal.c.

No functional changes.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4

Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20221220120655.19389-3-kvalo@kernel.org