disable bluetooth in default configuration

target/linux/config/Config.in.bluetooth

@@ -82,7 +82,6 @@ config ADK_KERNEL_BT_HCIBTSDIO
 	tristate
 	select ADK_KERNEL_BT
 	depends on ADK_TARGET_WITH_SDIO
-	default m if ADK_TARGET_SYSTEM_SOLIDRUN_IMX6
 	default n
 	help
 	  Bluetooth HCI SDIO driver.
@@ -127,7 +126,6 @@ config ADK_KERNEL_BT_MRVL_SDIO
 	select ADK_KERNEL_BT_MRVL
 	select ADK_KERNEL_BT_HCIBTSDIO
 	depends on ADK_TARGET_WITH_SDIO
-	default m if ADK_TARGET_SYSTEM_SOLIDRUN_IMX6
 	default n
 	help
 	  Bluetooth Marvell driver.