dt-bindings: sram: Allow numbers in sram region node name

Sram regions node name describes the region of reserved memory and can
be names such as l3cache@1000. Permit numbers to be used as part of the
reserved memory node name.

Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20211012154833.14111-1-nm@ti.com


Signed-off-by: Rob Herring <robh@kernel.org>