efi/boot: Don't free ebmalloc area at all

efi/boot: Don't free ebmalloc area at all

Freeing part of the BSS back for general use proves to be problematic.  It is
not accounted for in xen_in_range(), causing errors when constructing the
IOMMU tables, resulting in a failure to boot.

Other smaller issues are that tboot treats the entire BSS as hypervisor data,
creating and checking a MAC of it on S3, and that, by being 1MB in size,
freeing it guarentees to shatter the hypervisor superpage mappings.

This is a stopgap fix to unblock master, while alternatives are discussed.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>