powerpc/math_emu/efp: Include module.h

When building with a recent version of clang, there are a couple of
errors around the call to module_init():

  arch/powerpc/math-emu/math_efp.c:927:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
  module_init(spe_mathemu_init);
  ^
  int
  arch/powerpc/math-emu/math_efp.c:927:13: error: a parameter list without types is only allowed in a function definition
  module_init(spe_mathemu_init);
              ^
  2 errors generated.

module_init() is a macro, which is not getting expanded because module.h
is not included in this file. Add the include so that the macro can
expand properly, clearing up the build failure.

Fixes: ac6f120369 ("powerpc/85xx: Workaroudn e500 CPU erratum A005")
[chleroy: added fixes tag]
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/8403854a4c187459b2f4da3537f51227b70b9223.1662134272.git.christophe.leroy@csgroup.eu

arch/powerpc/math-emu/math_efp.c

@@ -17,6 +17,7 @@
 
 #include <linux/types.h>
 #include <linux/prctl.h>
+#include <linux/module.h>
 
 #include <linux/uaccess.h>
 #include <asm/reg.h>