BaseTools: Fix byte orders when handling 8-byte array

BaseTools: Fix byte orders when handling 8-byte array

Per UEFI spec, FibreEx.WWN, FibreEx.Lun, SasEx.Address, SasEx.Lun
and iSCSI.Lun are all 8-byte array with byte #0 in the left.
It means "0102030405060708" should be converted to:
    UINT8[8] = {01, 02, 03, 04, 05, 06, 07, 08}
or  UINT64 = {0807060504030201}

Today's implementation wrongly uses the reversed order.
The patch fixes this issue by using StrHexToBytes().
Copy this solution from MdePkg Hash version d0196be.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Yonghong Zhu <yonghong.zhu@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>