arm64: defconfig: Enable FSL_MC_BUS and FSL_MC_DPIO

Commit e8342cc7

 ("enable CAAM crypto engine on QorIQ DPAA2 SoCs")
enabled CRYPTO_DEV_FSL_DPAA2_CAAM, which depends on FSL_MC_DPIO,
which is not set. Enable FSL_MC_BUS, and build FSL_MC_DPIO and
CRYPTO_DEV_FSL_DPAA2_CAAM as modules.

Signed-off-by: Marc Gonzalez <marc.w.gonzalez@free.fr>
[olof: refreshed due to churn]
Signed-off-by: Olof Johansson <olof@lixom.net>