zephyr: Kconfig: fix task stack size option descriptions
zephyr: Kconfig: fix task stack size option descriptions

Change all task size description so that they mention the actual task
name rather than just "Stack size".

BRANCH=none
BUG=none
TEST=verified that the description shows up in menuconfig

Signed-off-by: Fabio Baltieri <1c55e39c05d9ab42261288cf330256b2af6ba179@google.com>
Change-Id: I2fd003d22ec59a474513b3287b408137e2605a99
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3593780
Reviewed-by: Al Semjonovs <c3a2ecb550cad1e7d5a943ca6241377f7b43ffc4@google.com>

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