ps1: gpu: Ensure hi >= lo when calling std::clamp()

[thentenaar]

On Lunar Disc 1, when entering Berg (about two minutes in,) going into Alex's house or the barn to the right of it, winds up causing an assertion failure in std::clamp() on the screen transition. Could be a bug in the game where it sends the 0xe3/0xe4 coords in the wrong order, or if it's off by one calculating them. Not sure if the real hardware ignores it or does anything in particular as a result.

Adding some print() calls in GPU::Render::triangle() before the clamp, I see:

v0=(320,216), v1=(336,216) v2=(320,232)
vmin.x=320, x1=160 x2=159
vmin.y=216, y1=112 y2=111
vmax.x=336, x1=160 x2=159
vmax.y=232, y1=112 y2=111

/usr/lib/gcc/x86_64-pc-linux-gnu/14/include/g++-v14/bits/stl_algo.h:3626: constexpr const _Tp& std::clamp(const _Tp&, const _Tp&, const _Tp&) [with _Tp = int]: Assertion '!(__hi < __lo)' failed.

Thus, this patch ensures hi >= lo.