x86/nmi: Consolidate NMI panic variables

x86/nmi: Consolidate NMI panic variables

Commit:

  c305a4e98378 ("x86: Move sysctls into arch/x86")

recently moved the sysctl handling of panic_on_unrecovered_nmi and
panic_on_io_nmi to x86-specific code. These variables no longer need to
be declared in the generic header file.

Relocate the variable definitions and declarations closer to where they
are used. This makes all the NMI panic options consistent and easier to
track.

[ mingo: Fixed up the SHA1 of the commit reference. ]

Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Cc: Joel Granados <joel.granados@kernel.org>
Link: https://lore.kernel.org/r/20250327234629.3953536-3-sohil.mehta@intel.com