ath: fix SPDX tags

Commit ec8f24b7 ("treewide: Add SPDX license identifier -
Makefile/Kconfig") marked various Makefiles and Kconfig files within ath
directories as GPL-2.0. But these modules and drivers are actually ISC:

* ath
* ar5523
* ath10k
* ath5k
* ath6kl
* ath9k
* wcn36xx
* wil6210

Fix SPDX tags accordingly.
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ath/Kconfig

-# SPDX-License-Identifier: GPL-2.0-only
+# SPDX-License-Identifier: ISC
 config ATH_COMMON
 	tristate
 

drivers/net/wireless/ath/Makefile

-# SPDX-License-Identifier: GPL-2.0
+# SPDX-License-Identifier: ISC
 obj-$(CONFIG_ATH5K)		+= ath5k/
 obj-$(CONFIG_ATH9K_HW)		+= ath9k/
 obj-$(CONFIG_CARL9170)		+= carl9170/

drivers/net/wireless/ath/ar5523/Kconfig

-# SPDX-License-Identifier: GPL-2.0-only
+# SPDX-License-Identifier: ISC
 config AR5523
        tristate "Atheros AR5523 wireless driver support"
        depends on MAC80211 && USB

drivers/net/wireless/ath/ar5523/Makefile

-# SPDX-License-Identifier: GPL-2.0-only
+# SPDX-License-Identifier: ISC
 obj-$(CONFIG_AR5523)   := ar5523.o

drivers/net/wireless/ath/ath10k/Kconfig

-# SPDX-License-Identifier: GPL-2.0-only
+# SPDX-License-Identifier: ISC
 config ATH10K
 	tristate "Atheros 802.11ac wireless cards support"
 	depends on MAC80211 && HAS_DMA

drivers/net/wireless/ath/ath5k/Kconfig

-# SPDX-License-Identifier: GPL-2.0-only
+# SPDX-License-Identifier: ISC
 config ATH5K
 	tristate "Atheros 5xxx wireless cards support"
 	depends on (PCI || ATH25) && MAC80211

drivers/net/wireless/ath/ath5k/Makefile

-# SPDX-License-Identifier: GPL-2.0
+# SPDX-License-Identifier: ISC
 ath5k-y				+= caps.o
 ath5k-y				+= initvals.o
 ath5k-y				+= eeprom.o

drivers/net/wireless/ath/ath6kl/Kconfig

-# SPDX-License-Identifier: GPL-2.0-only
+# SPDX-License-Identifier: ISC
 config ATH6KL
 	tristate "Atheros mobile chipsets support"
 	depends on CFG80211

drivers/net/wireless/ath/ath6kl/trace.h

-/* SPDX-License-Identifier: GPL-2.0 */
+/* SPDX-License-Identifier: ISC */
 #if !defined(_ATH6KL_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
 
 #include <net/cfg80211.h>

drivers/net/wireless/ath/ath9k/Kconfig

-# SPDX-License-Identifier: GPL-2.0-only
+# SPDX-License-Identifier: ISC
 config ATH9K_HW
 	tristate
 config ATH9K_COMMON

drivers/net/wireless/ath/ath9k/Makefile

-# SPDX-License-Identifier: GPL-2.0
+# SPDX-License-Identifier: ISC
 ath9k-y +=	beacon.o \
 		gpio.o \
 		init.o \

drivers/net/wireless/ath/wcn36xx/Kconfig

-# SPDX-License-Identifier: GPL-2.0-only
+# SPDX-License-Identifier: ISC
 config WCN36XX
 	tristate "Qualcomm Atheros WCN3660/3680 support"
 	depends on MAC80211 && HAS_DMA

drivers/net/wireless/ath/wcn36xx/Makefile

-# SPDX-License-Identifier: GPL-2.0
+# SPDX-License-Identifier: ISC
 obj-$(CONFIG_WCN36XX) := wcn36xx.o
 wcn36xx-y +=   main.o \
                dxe.o \

drivers/net/wireless/ath/wil6210/Kconfig

-# SPDX-License-Identifier: GPL-2.0-only
+# SPDX-License-Identifier: ISC
 config WIL6210
 	tristate "Wilocity 60g WiFi card wil6210 support"
 	select WANT_DEV_COREDUMP

drivers/net/wireless/ath/wil6210/Makefile

-# SPDX-License-Identifier: GPL-2.0
+# SPDX-License-Identifier: ISC
 obj-$(CONFIG_WIL6210) += wil6210.o
 
 wil6210-y := main.o