x86/cacheinfo: Apply maintainer-tip coding style fixes

The x86/cacheinfo code has been heavily refactored and fleshed out at
parent commits, where any necessary coding style fixes were also done
in place.

Apply Documentation/process/maintainer-tip.rst coding style fixes to the
rest of the code, and align its assignment expressions for readability.

Standardize on CPUID(n) when mentioning leaf queries.

Avoid breaking long lines when doing so helps readability.

At cacheinfo_amd_init_llc_id(), rename variable 'msb' to 'index_msb' as
this is how it's called at the rest of cacheinfo.c code.

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/20250324133324.23458-30-darwi@linutronix.de