Revert "i965: Advertise a line width of 40.0 on Cherryview and Skylake."

Revert "i965: Advertise a line width of 40.0 on Cherryview and Skylake."

This reverts commit f3b709c0ac073cd0ec90a3a0d91d1ee94668e043.

The "dEQP-GLES3.functional.rasterization.fbo.rbo_multisample_4.
interpolation.lines_wide" test appears to be broken on Cherryview when
we expose line widths greater than 12.0.  I'm not sure why.

For now, just go back to the limits we used on older platforms.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90902
Acked-by: Matt Turner <mattst88@gmail.com>