drm/i915/display: Remove PSR2 on JSL and EHL

While JSL and EHL eDP transcoder supports PSR2, the phy of this
platforms only supports eDP 1.3, so removing PSR2 support as this
feature was added in eDP 1.4.

Signed-off-by: Edmund Dea <edmund.j.dea@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210204175830.97857-1-jose.souza@intel.com