[DV] Create backdoor load for DRAM

[engdoreis]

After the backdoor is created, the SRAM tests should be removed and the DRAM should be used instead.

• Create DRAM backdoor
• Delete the sram from the target name in hjson
• Delete the sram binaries from cmake
• Clean up documentation (remove any explanation of the _sram binaries)

[engdoreis]

@marnovandermaas for visibility