intel/blorp: Fix a hang caused by invalid dispatch enables on gfx7

Because commit b9403b1c moved dispatch enable handling away from the compiler, the drivers must ensure correct dispatch enable values. This is handled by the intel_set_ps_dispatch_state function.

This patch fixes GPU hangs in some CTS tests like dEQP-VK.pipeline.monolithic.multisample.misc.input_attachments.r8g8b8a8_unorm_r16g16b16a16_sfloat_r32g32b32a32_uint_s8_uint.8x.ds_resolve_sample_zero.whole_framebuffer on Haswell.

Fixes: b9403b1c ("intel: factor out dispatch PS enabling logic")