intel_th: Add "rtit" source device

mainline inclusion
from mainline-v5.2-rc1
commit fc027f4c
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I47H3V


CVE: NA

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In some versions of Intel TH, the Software Trace Hub (STH) has a second
MMIO BAR dedicated to the input from Intel PT. This calls for a new
subdevice that will be enumerated if the corresponding BAR is present.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>