ARM: dts: SPEAr320: Boot the board in EXTENDED_MODE

On spear320 device supported mode are:

   * AUTO_NET_SMII_MODE
   * AUTO_NET_MII_MODE
   * AUTO_EXP_MODE
   * SMALL_PRINTERS_MODE
   * EXTENDED_MODE

spear320-evb board is designed for EXTENDED_MODE only, hence it does not
boot correctly in current form where pinctrl part for some devices fail.

Configure and boot the SPEAr320 evaluation board in EXTENDED_MODE.

Signed-off-by: Vipul Kumar Samar <vipulkumar.samar@st.com>
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>