oniro-linux.conf: Add more info about bootindex settings

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>
Signed-off-by: Luca Seritan <luca.seritan@huawei.com>

meta-oniro-core/conf/distro/oniro-linux.conf

@@ -87,7 +87,8 @@ MACHINE_FEATURES:qemux86-64 += "efi"
 MACHINE_FEATURES:qemux86 += "efi"
 
 # Add bootindex to qemu boot device to prevent boot order from being changed in ovmf file
-# and not break boot order with EFI. See qemuboot.bbclass for more information
+# and not break boot order with EFI. See qemuboot.bbclass for more information.
+# We set it here for the machines we don't have control on.
 QB_ROOTFS_EXTRA_OPT:qemux86-64 += ",bootindex=0"
 QB_ROOTFS_EXTRA_OPT:qemux86 += ",bootindex=0"