I have no other solutions for this problem - to flash modified BIOS you must disable SecureBoot in BIOS at first
Its GA-H110M-S2..Sorry for the confusion... I have already tried to modify the BIOS with Phoenix tool 2.66 using dynamic method with DELL Slic v2.3 and DELL SLP..and also got successful mod according to the tool..But somehow while flashing the modded bios using the included efiflash.exe ,it show as "Bad Bios "error..