mailbox: fix various typos in comments

Fix trivial typos in mailbox driver comments.

s/Intergrated/Integrated/
s/extenstion/extension/
s/atleast/at least/
s/commnunication/communication/
s/assgined/assigned/
s/commnunication/communication/
s/recevied/received/
s/succeded/succeeded/
s/implmentation/implementation/
s/definiation/definition/
s/traget/target/
s/wont/won't/

Cc: trivial@kernel.org
Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>