i965/vec4/tcs: Set conditional mod on TCS_OPCODE_SRC0_010_IS_ZERO.

i965/vec4/tcs: Set conditional mod on TCS_OPCODE_SRC0_010_IS_ZERO.

Missing this causes an assertion failure in the scheduler with the next
patch.

Additionally, this gives cmod propagation enough information to optimize
code better.

total instructions in shared programs: 7112991 -> 7112852 (-0.00%)
instructions in affected programs: 25704 -> 25565 (-0.54%)
helped: 139

total cycles in shared programs: 64812898 -> 64810674 (-0.00%)
cycles in affected programs: 127224 -> 125000 (-1.75%)
helped: 139

Acked-by: Francisco Jerez <currojerez@riseup.net>