commonlib: Consistently spell *romstage* without space

Make the spelling of *romstage* consistent without a space. Choose this
version, as *ramstage* is also spelled without a space, since commit
a7d924412a (timestamps: You can never have enough of them!).

Fixes: 0db924d74c (cbmem: print timestamp names)
Change-Id: I1b1c10393f0afb9a20ac916ff9dc140a51c716cd
Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-on: https://review.coreboot.org/21706
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/commonlib/include/commonlib/timestamp_serialized.h

@@ -123,7 +123,7 @@ static const struct timestamp_id_to_name {
 } timestamp_ids[] = {
 	/* Marker to report base_time. */
 	{ 0,			"1st timestamp" },
-	{ TS_START_ROMSTAGE,	"start of rom stage" },
+	{ TS_START_ROMSTAGE,	"start of romstage" },
 	{ TS_BEFORE_INITRAM,	"before ram initialization" },
 	{ TS_AFTER_INITRAM,	"after ram initialization" },
 	{ TS_END_ROMSTAGE,	"end of romstage" },