riscv: hibernation: Remove duplicate call of suspend_restore_csrs

riscv: hibernation: Remove duplicate call of suspend_restore_csrs

The suspend_restore_csrs is called in both __hibernate_cpu_resume
and the `else` of subsequent swsusp_arch_suspend.

Removing the first call makes both suspend_{save,restore}_csrs
left in swsusp_arch_suspend for clean code.

Fixes: c0317210012e ("RISC-V: Add arch functions to support hibernation/suspend-to-disk")
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: JeeHeng Sia <jeeheng.sia@starfivetech.com>
Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
Link: https://lore.kernel.org/r/20230522025020.285042-1-songshuaishuai@tinylab.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>