buildsystem: Determine the endianness only in the buildsystem

Let the buildsystem (make / meson) handle the endianness determination
and set the __FLASHROM_LITTLE_ENDIAN__ or __FLASHROM_BIG_ENDIAN__ macro
as cflag.

Change-Id: I37093528ae55e712cc30a0267a8ceac332750e7d
Signed-off-by: Thomas Heijligen <thomas.heijligen@secunet.de>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/58273
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
Original-Reviewed-by:  Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/72244
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/meson.build b/meson.build
index 1c7ffaa..28f15a0 100644
--- a/meson.build
+++ b/meson.build
@@ -29,6 +29,13 @@
 add_project_arguments('-D_BSD_SOURCE', language : 'c') # required for glibc < v2.19
 add_project_arguments('-DFLASHROM_VERSION="' + meson.project_version() + '"', language : 'c')
 
+if host_machine.endian() == 'little'
+  add_project_arguments('-D__FLASHROM_LITTLE_ENDIAN__=1', language : 'c')
+endif
+if host_machine.endian() == 'big'
+  add_project_arguments('-D__FLASHROM_BIG_ENDIAN__=1', language : 'c')
+endif
+
 # get defaults from configure
 config_atahpt = get_option('config_atahpt')
 config_atapromise = get_option('config_atapromise')