Refactor some alignment handling

Made using coccinelle:
  @@
  expression E;
  @@
  -(E + 7) & -8
  +ALIGN(E, 8)

  @@
  expression E;
  @@
  -(E + 15) & -16
  +ALIGN(E, 16)

Change-Id: I071d2c98cd95580d7de21d256c31b6368a3dc70b
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/910
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/mainboard/iwill/dk8_htx/acpi_tables.c b/src/mainboard/iwill/dk8_htx/acpi_tables.c
index ac1c692..b021214 100644
--- a/src/mainboard/iwill/dk8_htx/acpi_tables.c
+++ b/src/mainboard/iwill/dk8_htx/acpi_tables.c
@@ -181,7 +181,7 @@
 	get_bus_conf(); //it will get sblk, pci1234, hcdn, and sbdn
 
 	/* Align ACPI tables to 16byte */
-	start   = ( start + 0x0f ) & -0x10;
+	start   = ALIGN(start, 16);
 	current = start;
 
 	printk(BIOS_INFO, "ACPI: Writing ACPI tables at %lx...\n", start);
@@ -251,7 +251,7 @@
                         c  = (uint8_t) ('A' + i - 1 - 6);
                 }
                 printk(BIOS_DEBUG, "ACPI:    * SSDT for PCI%c Aka hcid = %d\n", c, sysconf.hcid[i]); //pci0 and pci1 are in dsdt
-                current = (current + 0x07) & -0x08;
+                current = ALIGN(current, 8);
                 ssdtx = (acpi_header_t *)current;
                 switch(sysconf.hcid[i]) {
                 case 1: //8132