x86/apic/32: Remove pointless default_acpi_madt_oem_check()

On 32bit there is no APIC implementing the acpi_madt_oem_check() except XEN
PV, but that does not matter at all.

generic_apic_probe() runs before ACPI tables are parsed. This selects the
XEN APIC if there is no command line override because the XEN APIC driver
is the first to be probed.

If there is a command line override then the XEN PV driver won't be
selected in the MADT OEM check either.

As there is no other MADT check implemented for 32bit APICs, this whole
excercise is a NOOP and can be removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)