Fix flash bank size for STM32F373
Fix flash bank size for STM32F373

The write protect granularity is 4-page instead of 2-page, so the bank
size should be 8K.

BRANCH=None
BUG=chrome-os-partner:32660
TEST=None

Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/223891
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
(cherry picked from commit 017b4478b238b3f32beca47fd7106c51ebca922e)
Signed-off-by: Duncan Laurie <70662b43bc1a20b57ded72a2b08be88dd0da4841@chromium.org>

Change-Id: Ifb8be289cc0d05cbe538062ad860727c9a652943
Reviewed-on: https://chromium-review.googlesource.com/225689
Tested-by: Duncan Laurie <70662b43bc1a20b57ded72a2b08be88dd0da4841@chromium.org>
Reviewed-by: Duncan Laurie <70662b43bc1a20b57ded72a2b08be88dd0da4841@chromium.org>
Commit-Queue: Duncan Laurie <70662b43bc1a20b57ded72a2b08be88dd0da4841@chromium.org>

thehobn/ec,thehobn/ec,thehobn/ec,thehobn/ec