x86/cpu, cpufreq: Remove AMD ELAN support

x86/cpu, cpufreq: Remove AMD ELAN support

Now that i486 and CONFIG_MELAN support has been removed upstream:

  8b793a92d862c ("x86/cpu: Remove M486/M486SX/ELAN support")

the CONFIG_ELAN_CPUFREQ and CONFIG_SC520_CPUFREQ cpufreq
drivers can be removed as well, as they depend on CONFIG_MELAN.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-pm@vger.kernel.org (open list:CPU FREQUENCY SCALING FRAMEWORK)
Link: https://lore.kernel.org/r/20250425084216.3913608-8-mingo@kernel.org