ath10k: add initial USB support

Chipsets like QCA9377 have support for USB so add initial USB bus
support to ath10k. With this patch we have the low level HIF and
HTC protocol working and it's possible to boot the firmware,
but it's still not possible to connect or anything like.

More changes are needed for full functionality. For that reason
we print during initialisation:

WARNING: ath10k USB support is incomplete, don't expect anything to work!

Signed-off-by: Erik Stromdahl <erik.stromdahl@gmail.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/Kconfig

@@ -29,6 +29,13 @@ config ATH10K_SDIO
 	  This module adds experimental support for SDIO/MMC bus. Currently
 	  work in progress and will not fully work.
 
+config ATH10K_USB
+	tristate "Atheros ath10k USB support (EXPERIMENTAL)"
+	depends on ATH10K && USB
+	---help---
+	  This module adds experimental support for USB bus. Currently
+	  work in progress and will not fully work.
+
 config ATH10K_DEBUG
 	bool "Atheros ath10k debugging"
 	depends on ATH10K

drivers/net/wireless/ath/ath10k/Makefile

@@ -30,5 +30,8 @@ ath10k_pci-$(CONFIG_ATH10K_AHB) += ahb.o
 obj-$(CONFIG_ATH10K_SDIO) += ath10k_sdio.o
 ath10k_sdio-y += sdio.o
 
+obj-$(CONFIG_ATH10K_USB) += ath10k_usb.o
+ath10k_usb-y += usb.o
+
 # for tracing framework to find trace.h
 CFLAGS_trace.o := -I$(src)