sbc: Fix for gcc 15 compile error

sbc: Fix for gcc 15 compile error

With the move to gcc 15, the code is now generating a compile error.

../sbc-2.1/sbc/sbc_primitives_armv6.c:284:9:
   error: too many arguments to function 'sbc_analyze_eight_armv6';
      expected 0, have 3

Simple fix is to drop the C standard down to gnu17 to avoid this new
error.

Signed-off-by: Ryan Eatmon <reatmon@ti.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>