xtensa: remove wrapper header for asm/param.h

xtensa's asm/device.h is a verbatim copy of asm-generic/device.h and
does not add any arch specific extensions. Thus, use the asm-generic
header directly.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>