ARM: dts: kzm9d: Fix W=1 dtc warnings

Warning (unit_address_vs_reg): Node /memory has a reg or ranges property, but no unit name
Warning (unit_address_vs_reg): Node /pfc@e0140200/serial@e1030000 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /gpio_keys/button@1 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /gpio_keys/button@2 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /gpio_keys/button@3 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /gpio_keys/button@4 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /regulator@0 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /regulator@1 has a unit name, but no reg property

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>