dev-arm: Remove the A9GlobalTimer

This is not used anymore

Change-Id: Ia25921cfe47e7f6b895450031abb740f94dc032d
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/31937
Tested-by: kokoro <noreply+kokoro@google.com>

src/dev/arm/SConscript

@@ -89,7 +89,6 @@ if env['TARGET_ISA'] == 'arm':
     Source('realview.cc')
     Source('rtc_pl031.cc')
     Source('timer_cpulocal.cc')
-    Source('timer_a9global.cc')
     Source('vgic.cc')
     Source('vio_mmio.cc')
     Source('ufs_device.cc')