complier.h: add __always_inline and use it in code base

Add a __always_inline macro that wraps __attribute__((always_inline))
and replace current users with the macro, excluding files under
src/vendorcode.

Change-Id: Ic57e474c1d2ca7cc0405ac677869f78a28d3e529
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/28587
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@google.com>

src/northbridge/intel/e7505/raminit.c

@@ -24,6 +24,7 @@
  * Steven James 02/06/2003
  */
 
+#include <compiler.h>
 #include <stdint.h>
 #include <device/pci_def.h>
 #include <arch/io.h>
@@ -911,7 +912,7 @@ static void configure_e7501_ram_addresses(const struct mem_controller
  *
  * NOTE: All cache and stack is lost during ECC scrub loop.
  */
-static inline void __attribute__((always_inline))
+static __always_inline void
 		initialize_ecc(unsigned long ret_addr, unsigned long ret_addr2)
 {
 	uint16_t scrubbed = pci_read_config16(MCHDEV, MCHCFGNS) & 0x08;