arm64/sysreg: Convert ID_DFR0_EL1 to automatic generation

Convert ID_DFR0_EL1 to be automatically generated as per DDI0487I.a,
no functional changes.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221130171637.718182-38-james.morse@arm.com


Signed-off-by: Will Deacon <will@kernel.org>