Add the capability to mark regions of the memory memory_type able of
hardware memory encryption.

Also add the capability to query if all regions of a memory node are
able to do hardware memory encryption.

Signed-off-by: Martin Fernandez <martin.fernandez@eclypsium.com>

Add a new member in the pg_data_t struct tell whether the node
corresponding to that pg_data_t is able to do hardware memory encryption.

Signed-off-by: Martin Fernandez <martin.fernandez@eclypsium.com>

Add a new member in e820_entry to hold whether an entry is able to do
hardware memory encryption or not.

Signed-off-by: Martin Fernandez <martin.fernandez@eclypsium.com>

Iterate over the EFI memmap finding the contiguous regions that are
able to do hardware encryption (ie, those who have the
EFI_MEMORY_CPU_CRYPTO enabled) and mark those in the e820_table.

Signed-off-by: Martin Fernandez <martin.fernandez@eclypsium.com>

Show in each node in sysfs if its memory is able to do hardware memory
encryption, ie. if all its memory is marked with EFI_MEMORY_CPU_CRYPTO
in the EFI memory map.

This value will only be shown if the memory is local to at least one
CPU, since otherwise it won't be able to be encrypted by CPU's
cryptographic capabilities. This check is done against the ACPI's SRAT
table.

Signed-off-by: Martin Fernandez <martin.fernandez@eclypsium.com>