fix(intel): support generic mailbox command in SiPSVC V3

Support generic mailbox command in the SiPSVC V3 framework
and add filter to avoid executing FCS related commands in
the generic mailbox format.

Change-Id: I682da2d37c68773ef34194abd6d49c52ddc5c26e
Signed-off-by: Girisha Dengi <girisha.dengi@intel.com>
Signed-off-by: Jit Loon Lim <jit.loon.lim@altera.com>
2 files changed