tpm_vtpm_proxy: fix address space of a user pointer in vtpmx_fops_ioctl()

When running make C=2 M=drivers/char/tpm/

  CC [M]  drivers/char/tpm//tpm_crb.o
  CHECK   drivers/char/tpm//tpm_vtpm_proxy.c
drivers/char/tpm//tpm_vtpm_proxy.c:552:32: warning: incorrect type in assignment (different address spaces)
drivers/char/tpm//tpm_vtpm_proxy.c:552:32:    expected struct vtpm_proxy_new_dev *vtpm_new_dev_p
drivers/char/tpm//tpm_vtpm_proxy.c:552:32:    got void [noderef] <asn:1>*argp
drivers/char/tpm//tpm_vtpm_proxy.c:553:51: warning: incorrect type in argument 2 (different address spaces)
drivers/char/tpm//tpm_vtpm_proxy.c:553:51:    expected void const [noderef] <asn:1>*from
drivers/char/tpm//tpm_vtpm_proxy.c:553:51:    got struct vtpm_proxy_new_dev *vtpm_new_dev_p
drivers/char/tpm//tpm_vtpm_proxy.c:559:34: warning: incorrect type in argument 1 (different address spaces)
drivers/char/tpm//tpm_vtpm_proxy.c:559:34:    expected void [noderef] <asn:1>*to
drivers/char/tpm//tpm_vtpm_proxy.c:559:34:    got struct vtpm_proxy_new_dev *vtpm_new_dev_p

The __user annotation was missing from the corresponding variable.

Fixes: 794c38e01358 ("tpm: Proxy driver for supporting multiple emulated TPMs")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Stefan Berger <stefanb@linux.vnet.ibm.com>