crypto: marvell - CRYPTO_DEV_OCTEONTX2_CPT should depend on ARCH_THUNDER2
The Marvell OcteonTX2 CPT physical function PCI device is present only
on OcteonTx2 SoC, and not available as an independent PCIe endpoint.
Hence add a dependency on ARCH_THUNDER2, to prevent asking the user
about this driver when configuring a kernel without OcteonTx2 platform
support.