include/linux/byteorder: import latest endian definitions from linux

u-boot's byteorder headers did not contain endianness attributions
for use with sparse, causing a lot of false positives.  Import the
kernel's latest definitions, and enable them by including compiler.h
and types.h.  They come with 'const' added for some swab functions, so
fix those up, too:

include/linux/byteorder/big_endian.h:46:2: warning: passing argument 1 of '__swab64p' discards 'const' qualifier from pointer target type [enabled by default]

Also, note: u-boot's historic __BYTE_ORDER definition has been
preserved (for the time being at least).

We also remove ad-hoc barrier() definitions, since we're including
compiler.h in files that hadn't in the past:

macb.c:54:0: warning: "barrier" redefined [enabled by default]

In addition, including compiler.h in byteorder changes the 'noinline'
definition to expand to __attribute__((noinline)).  This fixes
arch/powerpc/lib/bootm.c:

bootm.c:329:16: error: attribute '__attribute__': unknown attribute
bootm.c:329:16: error: expected ')' before '__attribute__'
bootm.c:329:25: error: expected identifier or '(' before ')' token

powerpc sparse builds yield:

include/common.h:356:22: error: marked inline, but without a definition

the unknown-reason inlining without a definition is considered obsolete
given it was part of the 2002 initial commit, and no arm version was
'fixed.'

also fixed:
ydirectenv.h:60:0: warning: "inline" redefined [enabled by default]

and:

Configuring for devconcenter - Board: intip, Options: DEVCONCENTER
make[1]: *** [4xx_ibm_ddr2_autocalib.o] Error 1
make: *** [arch/powerpc/cpu/ppc4xx/libppc4xx.o] Error 2
powerpc-fsl-linux-size: './u-boot': No such file
4xx_ibm_ddr2_autocalib.c: In function 'DQS_autocalibration':
include/asm/ppc4xx-sdram.h:1407:13: sorry, unimplemented: inlining failed in call to 'ppc4xx_ibm_ddr2_register_dump': function body not available
4xx_ibm_ddr2_autocalib.c:1243:32: sorry, unimplemented: called from here

and:

In file included from crc32.c:50:0:
crc32table.h:4:1: warning: implicit declaration of function '___constant_swab32' [-Wimplicit-function-declaration]
crc32table.h:4:1: error: initializer element is not constant
crc32table.h:4:1: error: (near initialization for 'crc32table_le[0]')

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
[trini: Remove '#endif' in include/common.h around setenv portion]
Signed-off-by: Tom Rini <trini@ti.com>