drm/nouveau/kms/nv04: remove set but unused variable.

The local variable `pclks` is defined and set but not used and can
therefore be removed.
Issue found by coccinelle.
Signed-off-by: NWambui Karuga <wambui.karugax@gmail.com>
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/dispnv04/arb.c

@@ -54,7 +54,7 @@ static void
 nv04_calc_arb(struct nv_fifo_info *fifo, struct nv_sim_state *arb)
 {
 	int pagemiss, cas, width, bpp;
-	int nvclks, mclks, pclks, crtpagemiss;
+	int nvclks, mclks, crtpagemiss;
 	int found, mclk_extra, mclk_loop, cbs, m1, p1;
 	int mclk_freq, pclk_freq, nvclk_freq;
 	int us_m, us_n, us_p, crtc_drain_rate;
@@ -69,7 +69,6 @@ nv04_calc_arb(struct nv_fifo_info *fifo, struct nv_sim_state *arb)
 	bpp = arb->bpp;
 	cbs = 128;
 
-	pclks = 2;
 	nvclks = 10;
 	mclks = 13 + cas;
 	mclk_extra = 3;