lib/Makefile.inc: Correct filename to master_header_pointer.c

Builds are failing sporadically with:

src/lib/master_header_pointer.c:5:10: fatal error: fmap_config.h: No such file or directory
    5 | #include <fmap_config.h>
      |          ^~~~~~~~~~~~~~~

Correct the filename in the Makefile from header_pointer.c to
master_header_pointer.c so that there's a dependency from
master_header_pointer.c to fmap_config.h.

Change-Id: I41bcb2a21fdbc48f09d5b6be3e211ca56607d849
Signed-off-by: Reka Norman <rekanorman@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64431
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Patrick Georgi <patrick@coreboot.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc
index a930663..57b0c7a 100644
--- a/src/lib/Makefile.inc
+++ b/src/lib/Makefile.inc
@@ -400,7 +400,7 @@
 cbfs_master_header-position := 0
 
 ifeq ($(CONFIG_ARCH_X86),y)
-$(call src-to-obj,bootblock,$(dir)/header_pointer.c): $(obj)/fmap_config.h
+$(call src-to-obj,bootblock,$(dir)/master_header_pointer.c): $(obj)/fmap_config.h
 bootblock-y += master_header_pointer.c
 else
 cbfs-files-y += header_pointer