ENGR00119274 TVE: HDTV can not work

1.arrange display port according to choice of different display device
2.for ipu_disp.c: not round pixel clock to even for tvout.
3.cmdline "hdtv" enable 720P, "hdtv=2" enable 720P as primary.

Signed-off-by: Jason Chen <b02280@freescale.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>