ARM: shmobile: r8a7779: Remove explicit SYSC config and init

If the R-Car H1 system controller is described in DT, the rcar-sysc
driver configures SYSCIER and SYSCIMR based on the SoC-specific power
area definitions in r8a7779-sysc.  The platform code still passed this
information to the rcar-sysc driver, for compatibility with old DTBs
predating commit b2df3aa4 ("ARM: dts: r8a7779: Add SYSC PM
Domains") in v4.7.  The time has come to drop backwards compatibility,
and delegate everything to the DT enabled rcar-sysc driver.

After stopping powering down secondary CPUs during early boot, there is
no longer a need to force an early initialization of the rcar-sysc
driver.  It will be initialized in time for secondary CPU bringup by its
early_initcall().

Hence all explicit SYSC configuration and initialization can be removed
from the R-Car H1 platform code.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>