platform/chrome: Fix typo in CROS_USBPD_NOTIFY help text

Correct the misspelling "platorms" to "platforms" in the help text
for the CROS_USBPD_NOTIFY Kconfig option.

Signed-off-by: Keenan Salandy <keenansalandy@gmail.com>
Link: https://lore.kernel.org/r/20250723140930.1443-1-keenansalandy@gmail.com


Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>