riscv: increase the environment size for the qemu-riscv platform to 128kB

The existing default size of 4kB is too small as the default environment
has already nearly that size and defining a single additional environment
variable can exceed the available space.

Signed-off-by: Karsten Merker <merker@debian.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/include/configs/qemu-riscv.h b/include/configs/qemu-riscv.h
index b7110ed..df22f78 100644
--- a/include/configs/qemu-riscv.h
+++ b/include/configs/qemu-riscv.h
@@ -20,7 +20,7 @@
 #define CONFIG_STANDALONE_LOAD_ADDR	0x80200000
 
 /* Environment options */
-#define CONFIG_ENV_SIZE			SZ_4K
+#define CONFIG_ENV_SIZE			SZ_128K
 
 #define BOOT_TARGET_DEVICES(func) \
 	func(QEMU, qemu, na) \