iscsi_ibft: Fix finding Broadcom specific ibft sign

commit 629c27aa upstream.

Search for Broadcom specific ibft sign "BIFT"
along with other possible values on UEFI

This patch is fix for regression introduced in
“935a9fee”.
https://lkml.org/lkml/2011/12/16/353

This impacts Broadcom CNA for iSCSI Boot on UEFI platform.
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

drivers/firmware/iscsi_ibft.c

@@ -756,6 +756,7 @@ static const struct {
 	 */
 	{ ACPI_SIG_IBFT },
 	{ "iBFT" },
+	{ "BIFT" },	/* Broadcom iSCSI Offload */
 };
 
 static void __init acpi_find_ibft_region(void)