tpm_crb: fix address space of the return pointer in crb_map_res()

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

  CHECK   drivers/char/tpm//tpm_crb.c
drivers/char/tpm//tpm_crb.c:248:31: warning: incorrect type in return expression (different address spaces)
drivers/char/tpm//tpm_crb.c:248:31:    expected void [noderef] <asn:2>*
drivers/char/tpm//tpm_crb.c:248:31:    got void *

CC: stable@vger.kernel.org
Fixes: 1bd047be ("tpm_crb: Use devm_ioremap_resource")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Stefan Berger <stefanb@linux.vnet.ibm.com>