board/orangepi/orangepi-r1/genimage.cfg: fix build after move to genimage 15

Fixes:
https://gitlab.com/buildroot.org/buildroot/-/jobs/1865935239

ERROR: hdimage(sdcard.img): part boot: 'partition-type' is only valid for mbr and hybrid partition-table-type

So change to partition-type-uuid instead.  With that fixed, genimage-15 then
also complains about the overlap between the u-boot partition and the GPT:

ERROR: hdimage(sdcard.img): partition [GPT array] (offset 0x100000, size 0x4000) overlaps previous partition u-boot (offset 0x2000, size 0x102000)

So adjust the u-boot partition to end just before the GPT.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

board/orangepi/orangepi-r1/genimage.cfg

@@ -24,11 +24,11 @@ image sdcard.img {
 		in-partition-table = "no"
 		image = "u-boot-sunxi-with-spl.bin"
 		offset = 8K
-		size = 1032K # 1MB - 8KB + 16KB(GPT)
+		size = 1016K # 1MB - 8KB
 	}
 
 	partition boot {
-		partition-type = 0xC
+		partition-type-uuid = "U"
 		bootable = "true"
 		image = "boot.vfat"
 	}
@@ -36,7 +36,7 @@ image sdcard.img {
 	# 'rootfs' will be used as the partition label, used
 	# with root=PARTLABEL=rootfs kernel command line
 	partition rootfs {
-		partition-type = 0x83
+		partition-type-uuid = "L"
 		image = "rootfs.ext4"
 		size = 512M
 	}