ARM: dts: arm: Update register-bit-led nodes 'reg' and node names

Add a 'reg' entry for register-bit-led nodes on the Arm Ltd platforms.
The 'reg' entry is the LED control register address. With this, the node
name can be updated to use a generic node name, 'led', and a
unit-address.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20211024232003.211484-1-linus.walleij@linaro.org'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>