x86/mm: Fix 'no5lvl' handling

x86/mm: Fix 'no5lvl' handling

early_identify_cpu() has to use early version of pgtable_l5_enabled()
that doesn't rely on cpu_feature_enabled().

Defining USE_EARLY_PGTABLE_L5 before all includes does the trick.

I lost the define in one of reworks of the original patch.

Fixes: 372fddf70904 ("x86/mm: Introduce the 'no5lvl' kernel parameter")
Signed-off-by: Kirill A. Shutemov <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]