riscv: sifive: unleashed: Set kernel_comp_addr_r for compressed kernel

Set kernel_comp_addr_r and kernel_comp_size for compressed kernel.
Adjust existing addresses for ramdisk, so that kernel_comp_addr_r
comes before the ramdisk image, since the decompressed kernel size
is known to us. This way we can allow big ramdisk image to be loaded.

Update unleashed.rst to remove the manual environment configuration
for compressed kernel boot.
Signed-off-by: NBin Meng <bmeng.cn@gmail.com>
Reviewed-by: NLeo Yu-Chi Liang <ycliang@andestech.com>

doc/board/sifive/unleashed.rst

@@ -216,8 +216,6 @@ Or if you want to use a compressed kernel image file such as Image.gz
             1.2 MiB/s
    done
    Bytes transferred = 4809458 (4962f2 hex)
-   =>setenv kernel_comp_addr_r 0x90000000
-   =>setenv kernel_comp_size 0x500000
 
 By this time, correct kernel image is loaded and required environment variables
 are set. You can proceed to load the ramdisk and device tree from the tftp server

include/configs/sifive-unleashed.h

@@ -61,12 +61,14 @@
 	"fdt_high=0xffffffffffffffff\0" \
 	"initrd_high=0xffffffffffffffff\0" \
 	"kernel_addr_r=0x84000000\0" \
-	"fdt_addr_r=0x88000000\0" \
-	"scriptaddr=0x88100000\0" \
+	"kernel_comp_addr_r=0x88000000\0" \
+	"kernel_comp_size=0x4000000\0" \
+	"fdt_addr_r=0x8c000000\0" \
+	"scriptaddr=0x8c100000\0" \
 	"script_offset_f=0x1fff000\0" \
 	"script_size_f=0x1000\0" \
-	"pxefile_addr_r=0x88200000\0" \
-	"ramdisk_addr_r=0x88300000\0" \
+	"pxefile_addr_r=0x8c200000\0" \
+	"ramdisk_addr_r=0x8c300000\0" \
 	"type_guid_gpt_loader1=" TYPE_GUID_LOADER1 "\0" \
 	"type_guid_gpt_loader2=" TYPE_GUID_LOADER2 "\0" \
 	"type_guid_gpt_system=" TYPE_GUID_SYSTEM "\0" \