usb: musb: tusb-dma can't be built-in if tusb is not

A configuration with CONFIG_USB_MUSB_HDRC=y, CONFIG_USB_TUSB_OMAP_DMA=y
and CONFIG_USB_MUSB_TUSB6010=m causes a link failure because of the
dependency on the tusb_get_revision symbol:

(.text+0x154ce8): undefined reference to `tusb_get_revision'

This patch ensures that either MUSB_HDRC and MUSB_TUSB6010 are
both modules or both built-in, which are the valid configurations.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: linux-omap@vger.kernel.org
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/musb/Kconfig

@@ -145,7 +145,7 @@ config USB_TI_CPPI41_DMA
 
 config USB_TUSB_OMAP_DMA
 	bool 'TUSB 6010'
-	depends on USB_MUSB_TUSB6010
+	depends on USB_MUSB_TUSB6010 = USB_MUSB_HDRC # both built-in or both modules
 	depends on ARCH_OMAP
 	help
 	  Enable DMA transfers on TUSB 6010 when OMAP DMA is available.