Add acpi_s3, acpi_s4 to the permitted list of platform flags
Add acpi_s3, acpi_s4 to the permitted list of platform flags

... so that any version of XenServer/XCP can have them by default, otherwise it would confuse testers when they're not using a server with advanced+ license.

Moreoever, it has no benefit to disallow these two particular flags on non-paid version (We don't support them anyway).

Signed-off-by: Zheng Li <fff69bf00b8ec5b6098a1768eaaaa75f40b8795d@eu.citrix.com>

koushikcgit/xcp-rrdd,robhoes/squeezed,djs55/xcp-rrdd,djs55/xcp-networkd,koushikcgit/xcp-networkd,koushikcgit/xcp-rrdd,johnelse/xcp-rrdd,djs55/xcp-networkd,simonjbeaumont/xcp-rrdd,sharady/xcp-networkd,simonjbeaumont/xcp-rrdd,johnelse/xcp-rrdd,djs55/xcp-rrdd,sharady/xcp-networkd,koushikcgit/xcp-rrdd,djs55/squeezed,koushikcgit/xcp-networkd