dt-bindings: arm: bcm: fix BCM53012 and BCM53016 SoC strings

Fix inaccurate SoC strings brcm,brcm53012 and brcm,brcm53016 to respectively
brcm,bcm53012 and brcm,bcm53016.

Fixes: 4cb5201f ("dt-bindings: arm: bcm: Convert BCM4708 to YAML")
Fixes: a2e385f5 ("dt-bindings: ARM: add bindings for the Meraki MR32")
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>