drivers: thermal: qmi_cooling: Treat all devices as max type devices

There is no low threshold monitor governor and min_state ops
support anymore in thermal framework. Treat all qmi cooling devices
as max mitigation type by default.

Change-Id: I6687d22a3e81411b6f4d691d2595122e334895f9
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>