riscv: Remove duplicate CLINT_TIMER selections

Since commit f862bbf ("riscv: Allow NOMMU kernels to run in
S-mode") in v6.10, CLINT_TIMER is selected by the main RISCV symbol when
RISCV_M_MODE is enabled.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/ce55529a42fa232cacd580e38866c60701f91095.1738764474.git.geert+renesas@glider.be
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>

Author: geertu

arch/riscv/Kconfig.socs

@@ -59,7 +59,6 @@ config ARCH_THEAD
 
 config ARCH_VIRT
 	bool "QEMU Virt Machine"
-	select CLINT_TIMER if RISCV_M_MODE
 	select POWER_RESET
 	select POWER_RESET_SYSCON
 	select POWER_RESET_SYSCON_POWEROFF
@@ -79,7 +78,6 @@ config ARCH_CANAAN
 config SOC_CANAAN_K210
 	bool "Canaan Kendryte K210 SoC"
 	depends on !MMU && ARCH_CANAAN
-	select CLINT_TIMER if RISCV_M_MODE
 	select ARCH_HAS_RESET_CONTROLLER
 	select PINCTRL
 	select COMMON_CLK