arm64: dts: zynqmp: Remove additional compatible string for i2c IPs

DT binding permits only one compatible string which was decribed in past by
commit 63cab195 ("i2c: removed work arounds in i2c driver for Zynq
Ultrascale+ MPSoC").
The commit aea37006 ("dt-bindings: i2c: cadence: Migrate i2c-cadence
documentation to YAML") has converted binding to yaml and the following
issues is reported:
...: i2c@ff030000: compatible: Additional items are not allowed
('cdns,i2c-r1p10' was unexpected)
	From schema:
.../Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml fds
...: i2c@ff030000: compatible: ['cdns,i2c-r1p14', 'cdns,i2c-r1p10'] is too
long

The commit c415f9e8 ("ARM64: zynqmp: Fix i2c node's compatible string")
has added the second compatible string but without removing origin one.
The patch is only keeping one compatible string "cdns,i2c-r1p14".

Fixes: c415f9e8 ("ARM64: zynqmp: Fix i2c node's compatible string")
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/cc294ae1a79ef845af6809ddb4049f0c0f5bb87a.1598259551.git.michal.simek@xilinx.com


Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>