ARM: shmobile: defconfig: Enable r8a7742 SoC

Enable recently added r8a7742 (RZ/G1H) SoC.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@bp.renesas.com>
Link: https://lore.kernel.org/r/1588197415-13747-3-git-send-email-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm/configs/shmobile_defconfig

@@ -179,6 +179,7 @@ CONFIG_ARCH_R7S72100=y
 CONFIG_ARCH_R7S9210=y
 CONFIG_ARCH_R8A73A4=y
 CONFIG_ARCH_R8A7740=y
+CONFIG_ARCH_R8A7742=y
 CONFIG_ARCH_R8A7743=y
 CONFIG_ARCH_R8A7744=y
 CONFIG_ARCH_R8A7745=y