thunderbolt: Fix build error in switch.c

Fixes the below error:
drivers/thunderbolt/switch.c:347:2: error: implicit declaration of function ‘kzalloc’ [-Werror=implicit-function-declaration]
drivers/thunderbolt/switch.c:381:2: error: implicit declaration of function ‘kcalloc’ [-Werror=implicit-function-declaration]

Signed-off-by: Sachin Kamat <sachin.kamat@samsung.com>
Acked-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>