Rules.mak: Rearrange appending UCLIBC_EXTRA_CFLAGS to CFLAGS
Rules.mak: Rearrange appending UCLIBC_EXTRA_CFLAGS to CFLAGS

UCLIBC_EXTRA_CFLAGS is currently added before the OPTIMIZATION flags
and OPTIMIZATION is chosen to be Os by default. But in OE we pass the optimisation
flags through UCLIBC_EXTRA_CFLAGS but they are not effective since -Os is
specified at last. So we need to change the order of these option flags

Signed-off-by: Khem Raj <729d64b6f67515e258459a5f6d20ec88b2caf8df@gmail.com>

m-labs/uclibc-lm32,ndmsystems/uClibc,foss-xtensa/uClibc,majek/uclibc-vx32,mephi42/uClibc,kraj/uclibc-ng,hjl-tools/uClibc,m-labs/uclibc-lm32,ffainelli/uClibc,groundwater/uClibc,majek/uclibc-vx32,foss-for-synopsys-dwc-arc-processors/uClibc,czankel/xtensa-uclibc,ddcc/klee-uclibc-0.9.33.2,ddcc/klee-uclibc-0.9.33.2,czankel/xtensa-uclibc,hjl-tools/uClibc,groundwater/uClibc,brgl/uclibc-ng,wbx-github/uclibc-ng,ndmsystems/uClibc,mephi42/uClibc,foss-xtensa/uClibc,kraj/uClibc,ndmsystems/uClibc,ffainelli/uClibc,kraj/uClibc,wbx-github/uclibc-ng,atgreen/uClibc-moxie,waweber/uclibc-clang,kraj/uclibc-ng,mephi42/uClibc,m-labs/uclibc-lm32,skristiansson/uClibc-or1k,kraj/uclibc-ng,ndmsystems/uClibc,ffainelli/uClibc,hwoarang/uClibc,czankel/xtensa-uclibc,foss-for-synopsys-dwc-arc-processors/uClibc,skristiansson/uClibc-or1k,brgl/uclibc-ng,hwoarang/uClibc,brgl/uclibc-ng,mephi42/uClibc,ddcc/klee-uclibc-0.9.33.2,groundwater/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,hwoarang/uClibc,foss-xtensa/uClibc,waweber/uclibc-clang,ddcc/klee-uclibc-0.9.33.2,czankel/xtensa-uclibc,groundwater/uClibc,groundwater/uClibc,waweber/uclibc-clang,skristiansson/uClibc-or1k,majek/uclibc-vx32,wbx-github/uclibc-ng,hjl-tools/uClibc,brgl/uclibc-ng,kraj/uclibc-ng,hwoarang/uClibc,waweber/uclibc-clang,hjl-tools/uClibc,wbx-github/uclibc-ng,atgreen/uClibc-moxie,kraj/uClibc,foss-xtensa/uClibc,hjl-tools/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,ffainelli/uClibc,ffainelli/uClibc,majek/uclibc-vx32,atgreen/uClibc-moxie,atgreen/uClibc-moxie,skristiansson/uClibc-or1k,kraj/uClibc,m-labs/uclibc-lm32