[platform][qemu-arm] switch to using the virtual timer interrupt

On mac qemu, trying to use the physical timer does not seem to work, but
really the virtual timer is what you should be using most of the time,
especially when running under emulation.

platform/qemu-virt-arm/platform.c

@@ -64,7 +64,7 @@ void platform_early_init(void) {
     /* initialize the interrupt controller */
     arm_gic_init();
 
-    arm_generic_timer_init(ARM_GENERIC_TIMER_PHYSICAL_INT, 0);
+    arm_generic_timer_init(ARM_GENERIC_TIMER_VIRTUAL_INT, 0);
 
     struct pl011_config uart_config = {
         .base = UART_BASE,

platform/qemu-virt-arm/rules.mk

@@ -41,9 +41,10 @@ GLOBAL_DEFINES += \
     MEMBASE=$(MEMBASE) \
     MEMSIZE=$(MEMSIZE) \
     PLATFORM_SUPPORTS_PANIC_SHELL=1 \
-    CONSOLE_HAS_INPUT_BUFFER=1
+    CONSOLE_HAS_INPUT_BUFFER=1 \
+    TIMER_ARM_GENERIC_SELECTED=CNTV
 
-GLOBAL_DEFINES += MMU_WITH_TRAMPOLINE=1 \
+GLOBAL_DEFINES += MMU_WITH_TRAMPOLINE=1
 
 LINKER_SCRIPT += \
     $(BUILDDIR)/system-onesegment.ld