[sle][migration][SLE15SP4] need to update the setting for x86_64 cases to fix the booting to grub2 issue
Bugs in existing tests
Based on poo#99156, need to update setting for x86_64 cases:
Including the sles daily, hpc daily, sles milestone and hpc milestone
Update the following items:
- add BOOT_HDD_IMAGE=1 for online cases
- remove QEMUVGA=std from flavor
- change 64bit_cirrus to 64bit in yaml Then trigger the cases.