serial: omap: Remove the hardcode serial_omap_console_ports array.

Currently the array serial_omap_console_ports is hard coded to 4.
Make it depend on the maximum uart count.
Post to [cfc55bcc ARM: OMAP2+: serial: Change MAX_HSUART_PORTS to 6]
the max ports is 6.

Cc: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>