MAINTAINERS: add Nick as Reviewer for compiler_attributes.h

$ ./scripts/get_maintainer.pl --rolestats --git-blame -f \
  include/linux/compiler_attributes.h
...
Nick Desaulniers <[email protected]> (supporter:CLANG/LLVM BUILD
SUPPORT,authored lines:43/331=13%,commits:8/15=53%)

It's also important for me to stay up on which compiler attributes clang
is missing.

Signed-off-by: Nick Desaulniers <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>

Author: nickdesaulniers

MAINTAINERS

@@ -4575,6 +4575,7 @@ F:	drivers/platform/x86/compal-laptop.c
 
 COMPILER ATTRIBUTES
 M:	Miguel Ojeda <[email protected]>
+R:	Nick Desaulniers <[email protected]>
 S:	Maintained
 F:	include/linux/compiler_attributes.h