reset: brcmstb: Enable reset drivers for ARCH_BCM2835

reset: brcmstb: Enable reset drivers for ARCH_BCM2835

The BRCMSTB and BRCMSTB_RESCAL reset drivers are also
used in the BCM2712, AKA the RPi5. The RPi platforms
have typically used the ARCH_BCM2835, and the PCIe
support for this SoC can use this config which depends
on these drivers so enable building them when just that
arch option is enabled to ensure the platform works as
expected.

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20250630175301.846082-1-pbrobinson@gmail.com
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>