fastboot: Add pvmfw

The pvmfw partition holds the protected VM firmware that is used by
Protected KVM to bootstrap the trust in protected VMs. Teach fastboot
about the partition so it gets flashed with flashall.

pvmfw is an AVB chained partition so is marked as BootCritical to allow
ABL's AVB verification to pass.

Test: tab complete and flashall
Bug: 171280178
Change-Id: Ie4cc478de25a945bc510488d87c2bee3aa5031f2
diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index 62f6ac7..f7edf8e 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -147,6 +147,7 @@
     { "odm",      "odm.img",          "odm.sig",      "odm",      true,  ImageType::Normal },
     { "odm_dlkm", "odm_dlkm.img",     "odm_dlkm.sig", "odm_dlkm", true,  ImageType::Normal },
     { "product",  "product.img",      "product.sig",  "product",  true,  ImageType::Normal },
+    { "pvmfw",    "pvmfw.img",        "pvmfw.sig",    "pvmfw",    true,  ImageType::BootCritical },
     { "recovery", "recovery.img",     "recovery.sig", "recovery", true,  ImageType::BootCritical },
     { "super",    "super.img",        "super.sig",    "super",    true,  ImageType::Extra },
     { "system",   "system.img",       "system.sig",   "system",   false, ImageType::Normal },