ARM: multi_v7_defconfig: Enable BQ32000 RTC driver

The iWave RZ/G1M Q7 SOM supports RTC (TI BQ32000).
To increase hardware support enable the driver in the
multi_v7_defconfig multiplatform configuration.

Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>