Initial riscv64 support

Most of the changes are self-explanatory and just follow what's
already happening for existing architectures.

Two things are worth pointing out:

  * we need to use shim-unsigned instead of shim-signed because
    riscv64 is not fully integrated into Fedora yet and so we
    can't do Secure Boot signing for the time being;

  * we use ext4 as bootfilesystem since in most cases the
    underlying firmware is going to be U-Boot, which needs to be
    able to load the board's DTB from /boot and doesn't support
    XFS.

Signed-off-by: David Abdurachmanov <davidlt@rivosinc.com>

teams/server.xml

@@ -71,6 +71,24 @@
 			</oemconfig>
 		</type>
 	</preferences>
+	<preferences profiles="ServerVMDisk" arch="riscv64">
+		<type image="oem" format="qcow2"
+		      filesystem="xfs"
+		      kernelcmdline="earlycon console=ttyS0,115200n8"
+		      devicepersistency="by-uuid"
+		      bootpartition="true" bootpartsize="1000" bootfilesystem="ext4" efipartsize="100" firmware="uefi"
+		      rootfs_label="fedora"
+		      >
+			<bootloader name="grub2" console="serial" timeout="0"/>
+			<size unit="G">10</size>
+			<systemdisk>
+				<volume name="@root"/>
+			</systemdisk>
+			<oemconfig>
+				<oem-resize>false</oem-resize>
+			</oemconfig>
+		</type>
+	</preferences>
 	<preferences profiles="ServerDisk" arch="x86_64">
 		<type image="oem"
 		      filesystem="xfs"
@@ -139,6 +157,24 @@
 			</oemconfig>
 		</type>
 	</preferences>
+	<preferences profiles="ServerDisk" arch="riscv64">
+		<type image="oem"
+		      filesystem="xfs"
+		      kernelcmdline="earlycon console=ttyS0,115200n8"
+		      devicepersistency="by-uuid"
+		      bootpartition="true" bootpartsize="1000" bootfilesystem="ext4" efipartsize="100" firmware="uefi"
+		      rootfs_label="fedora"
+		      >
+			<bootloader name="grub2" console="serial" timeout="3" timeout_style="menu"/>
+			<size unit="G">10</size>
+			<systemdisk>
+				<volume name="@root"/>
+			</systemdisk>
+			<oemconfig>
+				<oem-resize>false</oem-resize>
+			</oemconfig>
+		</type>
+	</preferences>
 	<packages type="bootstrap" patternType="plusRecommended" profiles="ServerCore">
 		<package name="fedora-release-server"/>
 	</packages>