x86/fpu: Remove unnecessary CPUID level check

The CPUID level dependency table will entirely zap X86_FEATURE_XSAVE
if the CPUID level is too low.  This code is unreachable.  Kill it.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Chang S. Bae <chang.seok.bae@intel.com>
Link: https://lore.kernel.org/all/20241213205038.6E71F9A4%40davehans-spike.ostc.intel.com