x86/platform/uv: Check EFI Boot to set reboot type

Change to checking for EFI Boot type from previous check on if this
is a KDUMP kernel.  This allows for KDUMP kernels that can handle
EFI reboots.
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hedi Berriche <hedi.berriche@hpe.com>
Cc: Justin Ernst <justin.ernst@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190910145840.215091717@stormcage.eag.rdlabs.hpecorp.netSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/apic/x2apic_uv_x.c

@@ -15,6 +15,7 @@
 #include <linux/export.h>
 #include <linux/pci.h>
 #include <linux/acpi.h>
+#include <linux/efi.h>
 
 #include <asm/e820/api.h>
 #include <asm/uv/uv_mmrs.h>
@@ -1483,6 +1484,14 @@ static void __init build_socket_tables(void)
 	}
 }
 
+/* Check which reboot to use */
+static void check_efi_reboot(void)
+{
+	/* If EFI reboot not available, use ACPI reboot */
+	if (!efi_enabled(EFI_BOOT))
+		reboot_type = BOOT_ACPI;
+}
+
 /* Setup user proc fs files */
 static int proc_hubbed_show(struct seq_file *file, void *data)
 {
@@ -1567,6 +1576,8 @@ static __init int uv_system_init_hubless(void)
 	if (rc >= 0)
 		uv_setup_proc_files(1);
 
+	check_efi_reboot();
+
 	return rc;
 }
 
@@ -1700,12 +1711,7 @@ static void __init uv_system_init_hub(void)
 	/* Register Legacy VGA I/O redirection handler: */
 	pci_register_set_vga_state(uv_set_vga_state);
 
-	/*
-	 * For a kdump kernel the reset must be BOOT_ACPI, not BOOT_EFI, as
-	 * EFI is not enabled in the kdump kernel:
-	 */
-	if (is_kdump_kernel())
-		reboot_type = BOOT_ACPI;
+	check_efi_reboot();
 }
 
 /*