usb: diag_bridge: Rename driver and functions for clarity

This will hopefully disambiguate naming clashes between this bridge
driver and existing DIAG drivers.

* Rename diag_usb.c to diag_bridge.c
* Rename diag_{open,close,read,write} to diag_bridge_*
* Rename Kconfig symbol
* Fix module build

Change-Id: Ia5b4884a7d85e2fa8f8c3865044a074a51e84adc
Signed-off-by: Jack Pham <jackp@codeaurora.org>
diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
index 98e57d5..c5dcdbf 100644
--- a/drivers/usb/misc/Kconfig
+++ b/drivers/usb/misc/Kconfig
@@ -259,27 +259,29 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called yurex.
 
-config USB_QCOM_DIAG
-	tristate "USB Qualcomm diag port driver"
-	depends on USB && !USB_SERIAL_QUALCOMM
-	default n
+config USB_QCOM_DIAG_BRIDGE
+	tristate "USB Qualcomm diagnostic bridge driver"
+	depends on USB
 	help
-	  Say Y here if you want to use the diag ports provided
-	  by many Qualcomm chipsets.
+	  Say Y here if you have a Qualcomm modem device connected via USB that
+	  will be bridged in kernel space. This driver communicates with the
+	  diagnostic interface and allows for bridging with the diag forwarding
+	  driver.
 
 	  To compile this driver as a module, choose M here: the
-	  module will be called qcaux.  If unsure, choose N.
+	  module will be called diag_bridge.  If unsure, choose N.
 
-config USB_QCOM_DIAG_TEST
-	tristate "USB Qualcomm diag port unit test driver"
-	depends on USB && USB_QCOM_DIAG
-	default n
+config USB_QCOM_DIAG_BRIDGE_TEST
+	tristate "USB Qualcomm diagnostic bridge driver test"
+	depends on USB && USB_QCOM_DIAG_BRIDGE
 	help
-	  Say Y here if you want to use unit test diag port provided
-	  by many Qualcomm chipsets.
+	  Say Y here if you want to enable the test hook for the
+	  Qualcomm diag bridge driver. When enabled, this will create
+	  a debugfs file entry named "diag_bridge_test" which can be used
+	  to send a ping command to the diag port of the modem over USB.
 
 	  To compile this driver as a module, choose M here: the
-	  module will be called qcaux.  If unsure, choose N.
+	  module will be called diag_bridge_test.  If unsure, choose N.
 
 config USB_QCOM_DUN_BRIDGE
 	tristate "USB Qualcomm modem DUN bridge driver"