svga: Limit number of immediates in shader

imm {128.0, -128.0, 2.0, 3.0} is used for lit instruction which
is not used very frequently. So allocate it only if lit instruction is used.

Tested with mtt piglit and mtt glretrace

v2: As per Charmaine's comment

Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Charmaine Lee <charmainel@vmware.com>
1 file changed