printk/docs: Add extra integer types to printk-formats

A few commonly used integer types were absent from this table, so add
them.

Link: https://github.com/ClangBuiltLinux/linux/issues/378
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: http://lkml.kernel.org/r/20190303123647.22020-1-louis@kragniz.eu
Cc: pmladek@suse.com
Cc: geert+renesas@glider.be
Cc: andriy.shevchenko@linux.intel.com
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: clang-built-linux@googlegroups.com
Cc: ndesaulniers@google.com
Cc: jflat@chromium.org
Cc: Louis Taylor <louis@kragniz.eu>
Signed-off-by: Louis Taylor <louis@kragniz.eu>
[pmladek@suse.com: sorted both variants the same way by size]
Signed-off-by: Petr Mladek <pmladek@suse.com>

Documentation/core-api/printk-formats.rst

@@ -13,6 +13,10 @@ Integer types
 
 	If variable is of Type,		use printk format specifier:
 	------------------------------------------------------------
+		char			%hhd or %hhx
+		unsigned char		%hhu or %hhx
+		short int		%hd or %hx
+		unsigned short int	%hu or %hx
 		int			%d or %x
 		unsigned int		%u or %x
 		long			%ld or %lx
@@ -21,6 +25,10 @@ Integer types
 		unsigned long long	%llu or %llx
 		size_t			%zu or %zx
 		ssize_t			%zd or %zx
+		s8			%hhd or %hhx
+		u8			%hhu or %hhx
+		s16			%hd or %hx
+		u16			%hu or %hx
 		s32			%d or %x
 		u32			%u or %x
 		s64			%lld or %llx