bootstd: cros: Allow detection of any kernel partition
The existing ChromiumOS bootmeth only supports reading a single kernel
partition, either 2 or 4. In fact there are normally two options
available.
Use the GUID to detect kernel partitions, with the BOOTMETHF_ANY_PART
flag, so that bootstd does not require a valid filesystem before calling
the bootmeth.
Tidy up and improve the logging while we are here.
Signed-off-by: Simon Glass <[email protected]>
Suggested-by: Alper Nebi Yasak <[email protected]>
[trini: Add missing select of PARTITION_TYPE_GUID]
Signed-off-by: Tom Rini <[email protected]>