thunderbolt: Update Kconfig to allow building on other architectures.

Thunderbolt 3 and USB4 shouldn't be x86 only.

Tested on a SolidRun HoneyComb (ARM Cortex-A72) with a
Gigabyte Titan Ridge Thunderbolt 3 PCIe card (JHL7540).
Signed-off-by: David Manouchehri <david.manouchehri@riseup.net>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/Kconfig

@@ -2,7 +2,6 @@
 menuconfig USB4
 	tristate "Unified support for USB4 and Thunderbolt"
 	depends on PCI
-	depends on X86 || COMPILE_TEST
 	select APPLE_PROPERTIES if EFI_STUB && X86
 	select CRC32
 	select CRYPTO