vendorcode/amd/agesa/f1{0,2,4,5}: Typo in header guard

Change-Id: I05d568f27f610c395e2638e79a7fd6646a407955
Found-by: Clang preprocessor wizard powers
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/7441
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Marc Jones <marc.jones@se-eng.com>