drm/radeon: remove set but not used variable 'tv_pll_cntl1'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/gpu/drm/radeon/radeon_legacy_tv.c: In function radeon_legacy_tv_mode_set:
drivers/gpu/drm/radeon/radeon_legacy_tv.c:538:24: warning: variable tv_pll_cntl1 set but not used [-Wunused-but-set-variable]

It is introduced by commit 4ce001ab ("drm/radeon/kms:
add initial radeon tv-out support."), but never used,
so remove it.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_legacy_tv.c

@@ -537,7 +537,7 @@ void radeon_legacy_tv_mode_set(struct drm_encoder *encoder,
 	uint32_t tv_master_cntl, tv_rgb_cntl, tv_dac_cntl;
 	uint32_t tv_modulator_cntl1, tv_modulator_cntl2;
 	uint32_t tv_vscaler_cntl1, tv_vscaler_cntl2;
-	uint32_t tv_pll_cntl, tv_pll_cntl1, tv_ftotal;
+	uint32_t tv_pll_cntl, tv_ftotal;
 	uint32_t tv_y_fall_cntl, tv_y_rise_cntl, tv_y_saw_tooth_cntl;
 	uint32_t m, n, p;
 	const uint16_t *hor_timing;
@@ -709,12 +709,6 @@ void radeon_legacy_tv_mode_set(struct drm_encoder *encoder,
 		(((n >> 9) & RADEON_TV_N0HI_MASK) << RADEON_TV_N0HI_SHIFT) |
 		((p & RADEON_TV_P_MASK) << RADEON_TV_P_SHIFT);
 
-	tv_pll_cntl1 = (((4 & RADEON_TVPCP_MASK) << RADEON_TVPCP_SHIFT) |
-			((4 & RADEON_TVPVG_MASK) << RADEON_TVPVG_SHIFT) |
-			((1 & RADEON_TVPDC_MASK) << RADEON_TVPDC_SHIFT) |
-			RADEON_TVCLK_SRC_SEL_TVPLL |
-			RADEON_TVPLL_TEST_DIS);
-
 	tv_dac->tv.tv_uv_adr = 0xc8;
 
 	if (tv_dac->tv_std == TV_STD_NTSC ||