Even when a variant has one or more of these defines set to 1, the
multiplier code paths are not used. Change the expression so that the
correct code paths are used.

arch/xtensa/lib/umulsidi3.S:44:38: warning: "XCHAL_NO_MUL" is not defined, evaluates to 0 [-Wundef]
   44 | #if defined(__XTENSA_CALL0_ABI__) && XCHAL_NO_MUL
arch/xtensa/lib/umulsidi3.S:145:38: warning: "XCHAL_NO_MUL" is not defined, evaluates to 0 [-Wundef]
  145 | #if defined(__XTENSA_CALL0_ABI__) && XCHAL_NO_MUL
arch/xtensa/lib/umulsidi3.S:159:5: warning: "XCHAL_NO_MUL" is not defined, evaluates to 0 [-Wundef]
  159 | #if XCHAL_NO_MUL

Fixes: 8939c58d ("xtensa: add __umulsidi3 helper")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Message-Id: <20230920052139.10570-16-rdunlap@infradead.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>