drivers: fpga: fix two trivial spelling mistakes

Trivial fix to two spelling mistakes
"execeeded" -> "exceeded"
"Invaild" -> "Invalid"

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>