arm64: dts: s32gxxxa-rdb: Add PCA85073A RTC module over I2C0

Add support for the PCA85073A RTC module connected via I2C0 on
S32G274A-RDB2 and S32G399A-RDB3 boards.

Note that the PCA85073A RTC module is not battery backed.

Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Matthias Brugger <mbrugger@suse.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>