Summary:
- This commit introduces a driver-specific spinlock to cxd56.c
to improve performance in SMP mode.
Impact:
- cxd56.c in SMP mode only
Testing:
- Tested with nxplayer and nxrecorder with the following configs
- spresense:wifi, spresense:wifi_smp
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>