ath11k: Add new dfs region name for JP

Japan has new Radar types as per latest regulatory,
included under MKK_N in FW. So adding new enum in
ath11k to support it.

Tested-on: IPQ8074 hw2.0 PCI WLAN.HK.2.4.0.1-00041-QCAHKSWPL_SILICONZ-1

Signed-off-by: Lavanya Suresh <lavaks@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1604563475-5782-1-git-send-email-lavaks@codeaurora.org