ARM: dts: s3c6410: remove additional CPU compatible

Only the specific compatible (arm,arm1176jzf-s) is allowed by dtschema:

  cpu@0: compatible: ['arm,arm1176jzf-s', 'arm,arm1176'] is too long
  cpu@0: compatible: Additional items are not allowed ('arm,arm1176' was unexpected)

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200907183313.29234-7-krzk@kernel.org