There might be instances where ath12k_dbg() is needed, but access to
struct ath12k_base (ab) is not readily available. To address this, add
support to print the debug message using printk() when ab is not present.
To avoid the need to explicitly pass NULL each time, introduce a new macro
ath12k_generic_dbg() which resolves to ath12k_dbg() with ab set to NULL.
Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-QCAHKSWPL_SILICONZ-1
Signed-off-by: Aditya Kumar Singh <aditya.kumar.singh@xxxxxxxxxxxxxxxx>