freedreno,tu: Don't request fragcoord components not being read.

freedreno,tu: Don't request fragcoord components not being read.

v1. Replace the existed bool type with new bitfield and edit register
files to take a mask instead of duplicating codes to do masking.

v2. Use fragcoord_compmask != 0 instead of fragcoord_compmask > 0 since
it represents a bitfield.

Tested with
  dEQP-VK.glsl.builtin_var.simple.fragcoord_xyz/w
  dEQP-GLES2.functional.shaders.builtin_variable.fragcoord_xyz/w

Closes: #2680
Signed-off-by: Hyunjun Ko <zzoon@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4723>