ARM: dts: aspeed-evb: Add unit name to memory node

[ Upstream commit e40ed274489a5f516da120186578eb379b452ac6 ]

Fixes a warning when building with W=1.

All of the ASPEED device trees build without warnings now.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>