Revert "riscv: dts: jh7110: Enable PLL node in SPL"

This patch breaks speed SD function on Milk-V Mars CM Lite (DFRobot mini router carrier).
Revert this commit for now.

Link: https://lore.kernel.org/u-boot/ZpZSmdrst4z_Q4JQ@swlinux02/T/#mbcd32d430fe58a1dd8161c9f3cc073052501b701



This reverts commit e6b7aeef.

Reported-by: E Shattow <lucent@gmail.com>
Signed-off-by: Leo Yu-Chi Liang <ycliang@andestech.com>