arm64: dts: ls1046a: fix dcfg address range

Dcfg was overlapping with clockgen address space which resulted
in failure in memory allocation for dcfg. According regs description
dcfg size should not be bigger than 4KB.

Signed-off-by: Zyta Szpak <zr@semihalf.com>
Fixes: 8126d881

 ("arm64: dts: add QorIQ LS1046A SoC support")
Signed-off-by: Shawn Guo <shawnguo@kernel.org>