bios: Use the correct offset for opcode 0x87
bios: Use the correct offset for opcode 0x87

Signed-off-by: Emil Velikov <ba34134066b5ebbd38fd9160ebb3f7340d29a979@nottingham.ac.uk>

envytools/envytools,MoochMcGee/envytools,envytools/envytools,karolherbst/envytools,pierremoreau/envytools,hakzsam/envytools,pierremoreau/envytools,karolherbst/envytools,karolherbst/envytools,envytools/envytools,kfractal/envytools,hakzsam/envytools,pierremoreau/envytools,pierremoreau/envytools,envytools/envytools,grate-driver/envytools,karolherbst/envytools,hakzsam/envytools,grate-driver/envytools,grate-driver/envytools,hakzsam/envytools,envytools/envytools,MoochMcGee/envytools,kfractal/envytools,kfractal/envytools,grate-driver/envytools,karolherbst/envytools,MoochMcGee/envytools,pierremoreau/envytools,hakzsam/envytools,MoochMcGee/envytools,kfractal/envytools,grate-driver/envytools,MoochMcGee/envytools,kfractal/envytools