arm64: dts: exynos: gs101: add samsung,sysreg property to CMU nodes

arm64: dts: exynos: gs101: add samsung,sysreg property to CMU nodes

With the exception of cmu_top, each CMU has a corresponding sysreg bank
that contains the BUSCOMPONENT_DRCG_EN and optional MEMCLK registers.
The BUSCOMPONENT_DRCG_EN register enables dynamic root clock gating of
bus components and MEMCLK gates the sram clock.

Now the clock driver supports automatic clock mode, provide the
samsung,sysreg property so the driver can enable dynamic root clock
gating of bus components and gate sram clock.

Note without the property specified the driver simply falls back to
previous behaviour of not configuring these registers so it is not an ABI
break.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Link: https://patch.msgid.link/20251222-automatic-clocks-v7-2-fec86fa89874@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>