ARM: imx_v6_v7_defconfig: enable driver of the LTC3676 PMIC

ARM: imx_v6_v7_defconfig: enable driver of the LTC3676 PMIC

The LTC3676 is a PMIC which is used on some i.MX6 based boards (like the
DHCOM i.MX6 Quad SoM), it was first used on the GW Ventana board, enable
LTC3676 driver in imx_v6_v7_defconfig.

Signed-off-by: Pascal Zimmermann <pzimmermann@dh-electronics.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@denx.de>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Marek Vasut <marex@denx.de>
Cc: kernel@dh-electronics.com
To: linux-arm-kernel@lists.infradead.org
Reviewed-by: Marek Vasut <marex@denx.de>
Tested-by: Marek Vasut <marex@denx.de> # On DH iMX6Q DHCOM PDK2
Signed-off-by: Shawn Guo <shawnguo@kernel.org>