drm/i915/psr: enable psr2 for y cordinate panels

Psr2 is enabled only for y cordinate panels.Once GTC (global time code)
is implemented,this restriction is removed so that psr2
can work on panels without y cordinate support.

v2: (Rodrigo)
- Move the check to intel_psr_match_conditions

v3: (Rodrigo)
- add return false

v4: rebase

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jim Bride <jim.bride@linux.intel.com>
Signed-off-by: Vathsala Nagaraju <vathsala.nagaraju@intel.com>
Signed-off-by: Patil Deepti <deepti.patil@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1484173710-3138-1-git-send-email-vathsala.nagaraju@intel.com