board: ti: am43xx: Enable hardware leveling

Remove the RDLVL_MASK, RDLVLGATE_MASK, WRLVL_MASK & enable
PHY_INVERT_CLKOUT to enable Hardware leveling for am437x
as recommended by EMIF Tools app note:

http://www.ti.com/lit/an/sprac70/sprac70.pdfSigned-off-by: NBrad Griffis <bgriffis@ti.com>
Signed-off-by: NKeerthy <j-keerthy@ti.com>

board/ti/am43xx/board.c

@@ -244,7 +244,7 @@ const struct emif_regs ddr3_emif_regs_400Mhz_production = {
 	.read_idle_ctrl			= 0x00050000,
 	.zq_config			= 0x50074BE4,
 	.temp_alert_config		= 0x0,
-	.emif_ddr_phy_ctlr_1		= 0x0E004008,
+	.emif_ddr_phy_ctlr_1		= 0x00048008,
 	.emif_ddr_ext_phy_ctrl_1	= 0x08020080,
 	.emif_ddr_ext_phy_ctrl_2	= 0x00000066,
 	.emif_ddr_ext_phy_ctrl_3	= 0x00000091,