hw/mips/fuloong2e: Correct cpuclock in PROM environment

hw/mips/fuloong2e: Correct cpuclock in PROM environment

Missed in 3ca7639ff00 ("hw/mips/fuloong2e: Set CPU frequency
to 533 MHz"), we need to tell the kernel the correct clock.

Fixes: 3ca7639ff00 ("hw/mips/fuloong2e: Set CPU frequency to 533 MHz").
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Reviewed-by: Huacai Chen <chenhuacai@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20201224031750.52146-7-jiaxun.yang@flygoat.com>
[PMD: Reworded]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>