ARM: dts: imx6sl: add missing properties for sram

stable inclusion
from stable-v5.10.150
commit 9735f2b62be928d96414ecadcf79ea45032ef059
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0XA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9735f2b62be928d96414ecadcf79ea45032ef059



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[ Upstream commit 60c9213a ]

All 3 properties are required by sram.yaml. Fixes the dtbs_check warning:
sram@900000: '#address-cells' is a required property
sram@900000: '#size-cells' is a required property
sram@900000: 'ranges' is a required property

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>