ARM: dts: s5pv210: Align i2c-gpio node names with dtschema

ARM: dts: s5pv210: Align i2c-gpio node names with dtschema

New dtschema v2025.6 enforces different naming on I2C nodes thus new
dtbs_check warnings appeared for I2C GPIO nodes:

  s5pv210-fascinate4g.dtb: i2c-gpio-0 (i2c-gpio):
    $nodename:0: 'i2c-gpio-0' does not match '^i2c(@.+|-[a-z0-9]+)?$'
  s5pv210-fascinate4g.dtb: i2c-gpio-0 (i2c-gpio):
    Unevaluated properties are not allowed ('#address-cells', '#size-cells', 'audio-codec@1a' were unexpected)

Rename the nodes to a generic i2c-[0-9]+ style with numbers continuing
the SoC I2C controller indexing (3 controllers) for simplicity and
obviousness, even if the SoC I2C controller is not enabled on given
board.  The names anyway would not conflict with SoC ones because of
unit addresses.

Verified with comparing two fdt (after fdtdump).

Reported-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Closes: https://lore.kernel.org/all/aCtD7BH5N_uPGkq7@shikoro/
Link: https://lore.kernel.org/r/20250612094807.62532-4-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>