msm: ADSPRPC: Restrict untrusted applications from attaching to GuestOS

Untrusted application can attach to guestOS and staticPD if it can
somehow make INIT IOCTL call with ATTACH flag. This is a potential
security issue as the untrusted application can crash guestOS or
staticPD. Restrict attach to guestOS or staticPD request if request
is being made using non-secure device node.

Change-Id: I322c7b242fd0baaf1c1bce2d83b992fecb0ca593
Acked-by: Ekansh Gupta <ekangupt@qti.qualcomm.com>
Signed-off-by: Vamsi Krishna Gattupalli <quic_vgattupa@quicinc.com>