platforms: fix imx8mq board timer frequency

The i.MX8MQ platforms use a clock frequency of 8333333 rather
than the 8000000 value which the -MP and MM platforms do.

This caused booting seL4 on these platforms to always print

        Warning:  gpt_cntfrq 8333333, expected 8000000

which seems to have actually been a correct warning.

Signed-off-by: Julia Vassiliki <julia.vassiliki@unsw.edu.au>

src/plat/imx8m-evk/config.cmake

@@ -20,6 +20,16 @@ if(KernelPlatformImx8mq-evk OR KernelPlatformImx8mm-evk OR KernelPlatformImx8mp-
     else()
         set(IMX8M_MAX_IRQ 160 CACHE INTERNAL "")
     endif()
+
+    if (KernelPlatformImx8mq-evk)
+        # per the DTS, clock-frequency = < 0x7f2815 >;
+        # also per gpt_cnfrq, which also reports 8333333
+        set(IMX8M_TIMER_FREQUENCY 8333333 CACHE INTERNAL "")
+    else()
+        # per the DTS, clock-frequency = < 0x7a1200 >;
+        set(IMX8M_TIMER_FREQUENCY 8000000 CACHE INTERNAL "")
+    endif()
+
     set(KernelArmCortexA53 ON)
     set(KernelArchArmV8a ON)
     set(KernelArmGicV3 ON)
@@ -31,7 +41,7 @@ if(KernelPlatformImx8mq-evk OR KernelPlatformImx8mm-evk OR KernelPlatformImx8mp-
         list(APPEND KernelDTSList "src/plat/imx8m-evk/overlay-imx8m-32bit.dts")
     endif()
     declare_default_headers(
-        TIMER_FREQUENCY 8000000
+        TIMER_FREQUENCY ${IMX8M_TIMER_FREQUENCY}
         MAX_IRQ ${IMX8M_MAX_IRQ}
         TIMER drivers/timer/arm_generic.h
         INTERRUPT_CONTROLLER arch/machine/gic_v3.h

src/plat/maaxboard/config.cmake

@@ -22,7 +22,7 @@ if(KernelPlatformMaaxboard)
         list(APPEND KernelDTSList "src/plat/maaxboard/overlay-${KernelPlatform}-32bit.dts")
     endif()
     declare_default_headers(
-        TIMER_FREQUENCY 8000000
+        TIMER_FREQUENCY 8333333
         MAX_IRQ 160
         TIMER drivers/timer/arm_generic.h
         INTERRUPT_CONTROLLER arch/machine/gic_v3.h