x86/cacheinfo: Rename 'struct _cpuid4_info_regs' to 'struct _cpuid4_info'

x86/cacheinfo: Rename 'struct _cpuid4_info_regs' to 'struct _cpuid4_info'

Parent commits decoupled amd_northbridge from _cpuid4_info_regs, moved
AMD L3 northbridge cache_disable_0/1 sysfs code to its own file, and
splitted AMD vs. Intel leaf 0x4 handling into:

    amd_fill_cpuid4_info()
    intel_fill_cpuid4_info()
    fill_cpuid4_info()

After doing all that, the "_cpuid4_info_regs" name becomes a mouthful.
It is also not totally accurate, as the structure holds cpuid4 derived
information like cache node ID and size -- not just regs.

Rename struct _cpuid4_info_regs to _cpuid4_info.  That new name also
better matches the AMD/Intel leaf 0x4 functions mentioned above.

Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250324133324.23458-17-darwi@linutronix.de