watchdog: hpwdt: clean up set_memory_x call for 32 bit

1. address has to be page aligned.
2. set_memory_x uses page size argument, not size.
Bug causes with following commit:
	commit da28179b4e90dda56912ee825c7eaa62fc103797
	Author: Mingarelli, Thomas <Thomas.Mingarelli@hp.com>
	Date:   Mon Nov 7 10:59:00 2011 +0100

     watchdog: hpwdt: Changes to handle NX secure bit in 32bit path

    commit e67d668 upstream.

    This patch makes use of the set_memory_x() kernel API in order
    to make necessary BIOS calls to source NMIs.

Signed-off-by: Maxim Uvarov <maxim.uvarov@oracle.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: stable <stable@vger.kernel.org>

drivers/watchdog/hpwdt.c

@@ -231,7 +231,7 @@ static int __devinit cru_detect(unsigned long map_entry,
 
 	cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
 
-	set_memory_x((unsigned long)bios32_entrypoint, (2 * PAGE_SIZE));
+	set_memory_x((unsigned long)bios32_map, 2);
 	asminline_call(&cmn_regs, bios32_entrypoint);
 
 	if (cmn_regs.u1.ral != 0) {
@@ -250,7 +250,8 @@ static int __devinit cru_detect(unsigned long map_entry,
 			cru_rom_addr =
 				ioremap(cru_physical_address, cru_length);
 			if (cru_rom_addr) {
-				set_memory_x((unsigned long)cru_rom_addr, cru_length);
+				set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
+					(cru_length + PAGE_SIZE - 1) >> PAGE_SHIFT);
 				retval = 0;
 			}
 		}