75bc21855142 drm/i915/display: define and use intel_reg_{offset, equal, valid}() helpers
75cde1f91f04 drm/i915/display: add struct intel_error_regs and use it
de788cc5dc0e drm/i915/display: add struct intel_irq_regs and use it
cb9dd77638ab drm/i915/display: add typedef for intel_reg_t and use it