ANDROID: KVM: arm64: mount procfs for pKVM module loading

modprobe needs /proc/cmdline to pass module arguments to the module
loader. Sadly, so early in the boot, nothing mounts that FS.

Bug: 301483379
Change-Id: Iaab3000e3b7f908fc81f7f36adf2f73c7d3129a4
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>