ath6kl: Fix a mismatch in power management debug message

Power Save Enabled : REC_POWER - conserve power
without sacrificing performance.
Power Save Disabled : MAX_PERF_POWER - maximum
performance at the expense of power.
Hence fix the debug message.

Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>