[as7816-64x] Update installer.conf (#10418)

Co-authored-by: ecsonic <ecsonic@edge-core.com>
Why I did it
The customer report of the PCIe Bus Errors upon the SDK initialization of as7816-64x.

How I did it
Based on the internal info and discussion, update "pcie_aspm=off" into ONIE_PLATFORM_EXTRA_CMDLINE_LINUX of installer.conf to resolve it.

device/accton/x86_64-accton_as7816_64x-r0/installer.conf

@@ -1,2 +1,2 @@
 CONSOLE_SPEED=115200
-ONIE_PLATFORM_EXTRA_CMDLINE_LINUX="tg3.short_preamble=1 tg3.bcm5718s_reset=1"
+ONIE_PLATFORM_EXTRA_CMDLINE_LINUX="tg3.short_preamble=1 tg3.bcm5718s_reset=1 pcie_aspm=off"