build: use 128MiB as the boot/kernel partition size on armvirt target
The nominal partition type for EFI boot partitions is FAT32,
which has a minimum size of 32MiB on a 512-byte-sector block device.
To ensure that the boot partition is created as FAT32 set a size
well above this minimum.
A useful discussion about EFI partition sizes can be found here:
https://superuser.com/questions/1310927/what-is-the-absolute-minimum-size-a-uefi-system-partition-can-be
I have found 128MiB works pretty consistently across both
tools (mkfs.fat) and firmwares (EDKII)
Signed-off-by: Mathew McBride <[email protected]>
Mathew McBride