arm64: dts: allwinner: h6: Add support for the SRAM C1 section

Add a node for H6 SRAM C1 section.

Manual calls it VE SRAM, but for consistency with older SoCs, SRAM C1
name is used.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>