entireflash: force fw_post.pad target as size of firmware may have changed
flyingf3: increase init stack size

FlyingF3 was blowing its init stack.  This leaves us
with at least 64-bytes of margin on the init stack with
a default configuration.
Removed non-standard encoding.
Converted some references to OPFW that got missed.
Fixed incorrect directory path.
Merge pull request #374 from solidgoldbomb/flyingf3-init-stack

flyingf3: increase init stack size
Merge pull request #376 from kubark42/non-standard-encoding

Removed non-standard encoding.
A couple more instances of opfw that needed to be converted to tlfw.
Merge pull request #379 from kubark42/fix-makefile-tlfw

Converted some references to OPFW that got missed.
Merge pull request #372 from lilvinz/fix_entireflash

entireflash: force fw_post.pad target as size of firmware may have changed