libflash/ecc: Remove hand rolled parity asm
libflash/ecc: Remove hand rolled parity asm

We get the same code generation using the builtin:

GCC 7.3:

   a3584:       7d 29 00 f4     popcntb r9,r9
   a3588:       7d 29 01 74     prtyd   r9,r9

GCC 6.3:

   a0bfc:       7d 29 00 f4     popcntb r9,r9
   a0c00:       7d 29 01 74     prtyd   r9,r9

Clang 7 (and clang 6):

   bd48c:       7c e7 03 f4     popcntd r7,r7
   bd490:       54 e7 07 fe     clrlwi  r7,r7,31

(Not sure why the clang builtin generates different code)

Signed-off-by: Joel Stanley <4816dabf8db1bc6cac35b3a24cab2ff844b5b0c7@jms.id.au>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.ibm.com>

legoater/skiboot,open-power/skiboot,stewart-ibm/skiboot,open-power/skiboot,qemu/skiboot,qemu/skiboot,legoater/skiboot,shenki/skiboot,open-power/skiboot,qemu/skiboot,legoater/skiboot,legoater/skiboot,legoater/skiboot,qemu/skiboot,stewart-ibm/skiboot,shenki/skiboot,open-power/skiboot,shenki/skiboot,shenki/skiboot,shenki/skiboot,stewart-ibm/skiboot,qemu/skiboot,open-power/skiboot