zephyr: remove workaround for shell when help is enabled
zephyr: remove workaround for shell when help is enabled

This workaround is no more needed, because hanging of shell
was fixed in zephyr code.

BRANCH=main
BUG=b:196627937
TEST=Shell is working correctly with lower size of buffer

Cq-Depend: chromium:3192860
Change-Id: I37627b60b7e645aeef7faf4a1e96a78e270d6660
Signed-off-by: Michał Barnaś <77666125932addc6fc525b281b518fd8fd2203d8@semihalf.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3194352
Commit-Queue: Jack Rosenthal <d3f605bef1867f59845d4ce6e4f83b8dc9e4e0ae@chromium.org>
Reviewed-by: Jack Rosenthal <d3f605bef1867f59845d4ce6e4f83b8dc9e4e0ae@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec