ARM: dts: r8a7791: Remove unit-address and reg from integrated cache

The Cortex-A15 cache controller is an integrated controller, and thus
the device node representing it should not have a unit-addresses or reg
property.

Fixes: 6f9314ce ("ARM: dts: r8a7791: Fix W=1 dtc warnings")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>