coresight: etm4x: Fix bit shifting

ctxid_pid and vmid_val in config are of type u64. When an integer
0xFF is being left shifted more than 32 bits, the behavior is
undefined. The fix is to specify 0xFF as an unsigned long.

Detected by Coverity scan: CID 37650, 37651 (Bad bit shift operation)

Signed-off-by: Bo Yan <byan@nvidia.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>