sys-boot/grub: backport EFI video fix

Signed-off-by: Mike Gilbert <floppym@gentoo.org>

sys-boot/grub/files/grub-2.14-efi_uga.patch

@@ -0,0 +1,41 @@
+https://gitlab.freedesktop.org/gnu-grub/grub/-/merge_requests/10
+
+From 129588e498647842c6f13f7809ef9ac583e2351b Mon Sep 17 00:00:00 2001
+From: Egor Ignatov <egori@altlinux.org>
+Date: Thu, 19 Mar 2026 17:22:11 +0500
+Subject: [PATCH] util/grub.d/00_header.in: Load efi_uga only on x86 EFI
+ platforms
+
+The efi_uga module is only built for i386-efi and x86_64-efi firmware), but
+commit ea0b76dc4a ("Disable loading all_video for EFI") loads it unconditionally
+on all EFI platforms. This causes a "file not found" error on aarch64-efi and
+other non-x86 EFI targets.
+
+Guard the insmod with a $grub_cpu check so the module is only
+loaded where it is actually available.
+
+Fixes: ea0b76dc4 ("util/grub.d/00_header.in: Disable loading all_video for EFI")
+
+Signed-off-by: Egor Ignatov <egori@altlinux.org>
+---
+ util/grub.d/00_header.in | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/util/grub.d/00_header.in b/util/grub.d/00_header.in
+index 77834cfaf..1afe41e67 100644
+--- a/util/grub.d/00_header.in
++++ b/util/grub.d/00_header.in
+@@ -135,7 +135,9 @@ else # GRUB_FORCE_EFI_ALL_VIDEO is not set true
+     cat <<EOF
+   if [ x\$grub_platform = xefi ]; then
+     insmod efi_gop
+-    insmod efi_uga
++    if [ x\$grub_cpu = xi386 -o x\$grub_cpu = xx86_64 ]; then
++      insmod efi_uga
++    fi
+   elif [ x\$feature_all_video_module = xy ]; then
+ EOF
+ fi # end GRUB_FORCE_EFI_ALL_VIDEO
+-- 
+GitLab
+

sys-boot/grub/grub-2.14-r4.ebuild

@@ -181,6 +181,7 @@ src_prepare() {
 
 	local PATCHES=(
 		"${WORKDIR}/${P}-patches"
+		"${FILESDIR}/${P}-efi_uga.patch"
 	)
 
 	default