nb/intel/ironlake/raminit_heci.c: Turn into compilation unit

Remove the temporary `raminit_heci.c` include and make it a proper
compilation unit. Export the `setup_heci_uma()` function.

Change-Id: Ia6782a0cb5e731d58764d0fa4ee256bfc8cef98a
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61929
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/northbridge/intel/ironlake/Makefile.inc

@@ -11,6 +11,7 @@ ramstage-y += gma.c
 
 romstage-y += memmap.c
 romstage-y += raminit.c
+romstage-y += raminit_heci.c
 romstage-y += raminit_tables.c
 romstage-y += early_init.c
 romstage-y += romstage.c

src/northbridge/intel/ironlake/raminit.c

@@ -1503,9 +1503,6 @@ static const struct ram_training *get_cached_training(void)
 					   NULL);
 }
 
-/* TODO: Remove */
-#include "raminit_heci.c"
-
 static int have_match_ranks(struct raminfo *info, int channel, int ranks)
 {
 	int ranks_in_channel;

src/northbridge/intel/ironlake/raminit.h

@@ -106,4 +106,6 @@ u16 get_max_timing(struct raminfo *info, int channel);
 void early_quickpath_init(struct raminfo *info, const u8 x2ca8);
 void late_quickpath_init(struct raminfo *info, const int s3resume);
 
+void setup_heci_uma(struct raminfo *info);
+
 #endif				/* RAMINIT_H */

src/northbridge/intel/ironlake/raminit_heci.c

@@ -193,7 +193,7 @@ static void send_heci_uma_message(const u64 heci_uma_addr, const unsigned int he
 		die("HECI init failed\n");
 }
 
-static void setup_heci_uma(struct raminfo *info)
+void setup_heci_uma(struct raminfo *info)
 {
 	if (!info->memory_reserved_for_heci_mb && !(pci_read_config32(HECIDEV, 0x40) & 0x20))
 		return;