vmxnet3: prevent building with 64K pages

I got a warning about broken code on ARM64 with 64K pages:

drivers/net/vmxnet3/vmxnet3_drv.c: In function 'vmxnet3_rq_init':
drivers/net/vmxnet3/vmxnet3_drv.c:1679:29: error: large integer implicitly truncated to unsigned type [-Werror=overflow]
    rq->buf_info[0][i].len = PAGE_SIZE;

'len' here is a 16-bit integer, so this clearly won't work. I don't think
this driver is used much on anything other than x86, so there is no need
to fix this properly and we can work around it with a Kconfig dependency
to forbid known-broken configurations. qemu in theory supports it on
other architectures too, but presumably only for compatibility with x86
guests that also run on vmware.

CONFIG_PAGE_SIZE_64KB is used on hexagon, mips, sh and tile, the other
symbols are architecture-specific names for the same thing.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>