MAINTAINERS: Add linux-renesas-soc@vger.kernel.org list for Renesas TMIO/SDHI driver

Add linux-renesas-soc@vger.kernel.org list entry for Renesas TMIO/SDHI
driver.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20220404174159.571-1-prabhakar.mahadev-lad.rj@bp.renesas.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>