imx: re-enable ARM arch timer

Config option `ARM_ARCH_TIMER` has been removed during rebasing onto
5.15 kernel in commit 2b395c2 ("imx: update config for 5.15").

Anyway, as stated in commit 8cdc356 ("mediatek: mt7623: Re-enable
ARM arch timer") config option `ARM_ARCH_TIMER` cannot be enabled in the
config directly; it is only selected by `HAVE_ARM_ARCH_TIMER`. We need
to enable the latter in our config.

Fixes: 2b395c2 ("imx: update config for 5.15")
Reported-by: Piotr Dymacz <pepe2k@gmail.com>
Signed-off-by: Petr Štetiar <ynezz@true.cz>

target/linux/imx/config-5.15

@@ -16,6 +16,7 @@ CONFIG_ARCH_SELECT_MEMORY_MODEL=y
 CONFIG_ARCH_SPARSEMEM_ENABLE=y
 CONFIG_ARCH_SUSPEND_POSSIBLE=y
 CONFIG_ARM=y
+CONFIG_ARM_ARCH_TIMER_EVTSTREAM=y
 CONFIG_ARM_CRYPTO=y
 CONFIG_ARM_ERRATA_754322=y
 CONFIG_ARM_ERRATA_764369=y
@@ -210,6 +211,7 @@ CONFIG_HARDIRQS_SW_RESEND=y
 CONFIG_HAS_DMA=y
 CONFIG_HAS_IOMEM=y
 CONFIG_HAS_IOPORT_MAP=y
+CONFIG_HAVE_ARM_ARCH_TIMER=y
 CONFIG_HAVE_SMP=y
 CONFIG_HWMON=y
 CONFIG_HW_RANDOM=y