board/friendlyarm/nanopc-t4: use partition-type-uuid in genimage.cfg

board/friendlyarm/nanopc-t4: use partition-type-uuid in genimage.cfg

Genimage 15 restricted the partition-type option to mbr and hybrid
partition-table-type and now prints a warning when it is used [1]:

ERROR: hdimage(disk.img): part boot: 'partition-type' is only valid for mbr and hybrid partition-table-type

[1] https://github.com/pengutronix/genimage/commit/1d72d8091f83790a0a35a1ea7dc25d46adba8876

So let's use for EFI System partition:
'partition-type-uuid = c12a7328-f81f-11d2-ba4b-00a0c93ec93b'
and for Root partition (64-bit ARM/AArch64):
'partition-type-uuid = b921b045-1df0-41c3-af44-4c6f280d3fae'

Fixes:
https://gitlab.com/buildroot.org/buildroot/-/jobs/1929717055

FTR, the magic UUID are from:
    https://en.wikipedia.org/wiki/GUID_Partition_Table#Partition_type_GUIDs

Signed-off-by: Giulio Benetti <[email protected]>
Signed-off-by: Thomas Petazzoni <[email protected]>