Introduce start symbol for riscv EFI

Hopefully this resolves:

    BUILDSTDERR: ././grub-mkimage: error: undefined symbol start.

Signed-off-by: David Abdurachmanov <david.abdurachmanov@sifive.com>

0001-Add-start-symbol.patch

@@ -0,0 +1,29 @@
+From 02db11b59d2e89a281df8fb526a3229626e52ff7 Mon Sep 17 00:00:00 2001
+From: Fedora Ninjas <grub2-owner@fedoraproject.org>
+Date: Sat, 9 Nov 2019 19:51:57 +0000
+Subject: [PATCH] Add start symbol
+
+All other architectures have start symbol.
+
+Hopefully this resolves:
+
+    BUILDSTDERR: ././grub-mkimage: error: undefined symbol start.
+---
+ grub-core/kern/riscv/efi/startup.S | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/grub-core/kern/riscv/efi/startup.S b/grub-core/kern/riscv/efi/startup.S
+index f2a7b2b..7817731 100644
+--- a/grub-core/kern/riscv/efi/startup.S
++++ b/grub-core/kern/riscv/efi/startup.S
+@@ -29,6 +29,7 @@
+ 
+ 	.file 	"startup.S"
+ 	.text
++FUNCTION(start)
+ FUNCTION(_start)
+ 	/*
+ 	 *  EFI_SYSTEM_TABLE and EFI_HANDLE are passed in a1/a0.
+-- 
+2.24.0
+

grub.patches

@@ -185,3 +185,4 @@ Patch0184: 0184-10_linux.in-Also-use-GRUB_CMDLINE_LINUX_DEFAULT-to-s.patch
 Patch0185: 0185-blscfg-Don-t-hardcode-an-env-var-as-fallback-for-the.patch
 Patch0200: 0001-Add-riscv64-to-150-patch.patch
 Patch0201: 0001-Adjust-0004-patch-to-incl.-riscv.patch
+Patch0202: 0001-Add-start-symbol.patch