x86/mm: Add INVLPGB feature and Kconfig entry

In addition, the CPU advertises the maximum number of pages that can be
shot down with one INVLPGB instruction in CPUID. Save that information
for later use.

  [ bp: use cpu_has(), typos, massage. ]

Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250226030129.530345-3-riel@surriel.com