grub: only enable nvme if needed on a board

remove nvme support from the "default" grub tree

now there are three trees:

* default: no xhci or nvme patches
* nvme: contains nvme support
* xhci: contains xhci and nvme support

this is in case a bug like lbmk issue #216 ever occurs
again, as referenced before during lbmk audit 5

there is no indication that the nvme patch causes any
issues, but after previous experience i want to be sure

Signed-off-by: Leah Rowe <leah@libreboot.org>

config/grub/nvme/patches/0004-prefix/0003-don-t-print-empty-error-messages.patch

@@ -0,0 +1,31 @@
+From e5b7ec81421487e71bcaf8b6b5a27f3649a62753 Mon Sep 17 00:00:00 2001
+From: Leah Rowe <leah@libreboot.org>
+Date: Sun, 5 Nov 2023 17:25:20 +0000
+Subject: [PATCH 1/1] don't print empty error messages
+
+this is part two of the quest to kill the prefix
+error message. after i disabled prefix-related
+messages, it still printed "error: ." on screen.
+
+Signed-off-by: Leah Rowe <leah@libreboot.org>
+---
+ grub-core/kern/err.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/grub-core/kern/err.c b/grub-core/kern/err.c
+index 53c734de7..7cac53983 100644
+--- a/grub-core/kern/err.c
++++ b/grub-core/kern/err.c
+@@ -107,7 +107,8 @@ grub_print_error (void)
+     {
+       if (grub_errno != GRUB_ERR_NONE)
+ 	{
+-	  grub_err_printf (_("error: %s.\n"), grub_errmsg);
++          if (grub_strlen(grub_errmsg) > 0)
++	    grub_err_printf (_("error: %s.\n"), grub_errmsg);
+ 	  grub_err_printed_errors++;
+ 	}
+     }
+-- 
+2.39.2
+