Drop unnecessary DEVICE_NOOP entries

Providing an explicit no-op function pointer is only necessary for
`.read_resources` and `.set_resources`. All other device-operation
pointers are optional and can be NULL.

Change-Id: I3d139f7be86180558cabec04b8566873062e33be
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40206
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/vendorcode/google/chromeos/chromeos.h

@@ -72,7 +72,7 @@ void mainboard_chromeos_acpi_generate(void);
 #if CONFIG(CHROMEOS)
 void chromeos_dsdt_generator(struct device *dev);
 #else
-#define chromeos_dsdt_generator DEVICE_NOOP
+#define chromeos_dsdt_generator NULL
 #endif
 
 enum {