ARM: dts: bcm2835/6: Add the missing L1/L2 cache information

This patch adds the cache info for the BCM2835 and BCM2836.
However, while testing I noticed that this is
not implemented for ARMv6/7.
Basically arch/arm/kernel/cacheinfo.c and other topology
related code is missing.
Since the work is already done and this has no negative effects,
I am submitting it for future/documentation purposes.

Signed-off-by: Richard Schleich <rs@noreya.tech>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>