xtensa: umulsidi3: fix conditional expression

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: 8939c58d68f9 ("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>

xtensa: add asm-prototypes.h

Move assembly source prototypes from xtensa_ksyms.c to
asm/asm-prototypes.h, move corresponding EXPORT_SYMBOLs to the assembly
sources and enable HAVE_ASM_MODVERSIONS for xtensa.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: add __umulsidi3 helper

xtensa gcc-13 has changed multiplication handling and may now use
__umulsidi3 helper where it used to use __muldi3. As a result building
the kernel with the new gcc may fail with the following error:

linux/init/main.c:1287: undefined reference to `__umulsidi3'

Fix the build by providing __umulsidi3 implementation for xtensa.

Cc: stable@vger.kernel.org # 5.18+
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>