Remove BOARD_PREBUILT_PVMFWIMAGE from the common board config

The pvmfw image is included by setting PRODUCT_BUILD_PVMFW_IMAGE in
device.mk and there shouldn't be this prebuilt override.

Bug: 199717422
Test: build
Change-Id: I0ba022e7b222ff89a4b2f991900abb3b4589396c
1 file changed