omap3_logic: Enable DM_SPI

With the introduction of ("Boards,Need,to,Switch,DM] spi: omap3_spi:
Full dm conversion"), Driver Model for McSPI is now available on the
omap3.  This enables the config by default on omap3_logic boards.

Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>

configs/omap3_logic_defconfig

@@ -47,6 +47,7 @@ CONFIG_SMC911X=y
 CONFIG_SMC911X_BASE=0x08000000
 CONFIG_SMC911X_32_BIT=y
 CONFIG_SYS_NS16550=y
+CONFIG_DM_SPI=y
 CONFIG_OMAP3_SPI=y
 CONFIG_USB=y
 CONFIG_USB_EHCI_HCD=y