drm: rockchip/dw_hdmi-rockchip: improve for HDMI electrical test

When pixel clock less than 148.5MHz, make sloopboost=2 tklvl=20
cklvl=13 increase rasing/falling time and increase data & clock
voltage driver.

When pixel clock less than 74.25MHz, make sloopboost=0 tklvl=19
cklvl=18, increase data and clock voltage driver.

Signed-off-by: Yakir Yang <ykk@rock-chips.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c

@@ -135,9 +135,9 @@ static const struct dw_hdmi_curr_ctrl rockchip_cur_ctr[] = {
 
 static const struct dw_hdmi_phy_config rockchip_phy_config[] = {
 	/*pixelclk   symbol   term   vlev*/
-	{ 74250000,  0x8009, 0x0004, 0x01ad},
-	{ 148500000, 0x8029, 0x0004, 0x01ad},
-	{ 297000000, 0x8039, 0x0005, 0x01ad},
+	{ 74250000,  0x8009, 0x0004, 0x0272},
+	{ 148500000, 0x802b, 0x0004, 0x028d},
+	{ 297000000, 0x8039, 0x0005, 0x028d},
 	{ ~0UL,	     0x0000, 0x0000, 0x0000}
 };